I am a nondenominational Christian. I became a Christian at the age of 23 after years of living in lust and following after wealth. I had no faith of any kind before this age aside from the occasional prayer to God when I was in trouble. This essay is by nature an opinion and includes many opinions. This essay is a work of faith and many statements are not backed up by anything scientific. For example, the phrase, "true knowledge of God" is unscientific and could make many cringe in distaste. However, it is my faith that the Holy Bible contains the true knowledge of God, and I analyze the Holy Scriptures with this belief. The essay is intended to elucidate to the greatest degree possible the true nature of the God we serve in the context of I.Q testing. I do not consider myself worthy to speak on behalf of all Christians. I believe God uses the weak to lead the strong. That being said, I consider myself a very weak man on many levels. I have consulted with leaders in the church and they have encouraged me to perform studies of this nature and write my thoughts as I have done here.
The key to answering this question involves understanding whether or not God as Christians understand Him would assign a number to a person that differentiates him or her from other people.
In this essay I reference both the Old Testament and the New Testament writings in the Holy Bible. Christians are no longer beholden to the Law of Moses or the laws and practices of the Old Testament as we are under the new covenant that Christ made in His perfectly atoning blood. Christ is the end of the law to all who believe (Romans 10:4). However, as it is written, the Old Testament is useful for instruction, teaching, and training in righteousness (2 Timothy 3:16-17). As it is very instructive, I have included Old Testament writings in this study.
It does not appear that there is any marked difference in God's tendency to differentiate between people in the Old and New Testaments with numbers. As it will be seen, the Old Testament differentiates between people based on numerical age, numerical income, number slain, numerical height, and the numerical family size. In the New Testament, namely in Matthew 25:14-30 and Luke 19:11-27, numbers of talents are given to servants based on ability. The honor and privilege received by the servants is based on the number of talents earned (i.e. performance) while serving in the kingdom. (It is the author's opinion and understanding that the talents symbolically represent human souls and the ability refers to saving souls and bearing good fruit according to Luke 15:8-10 where the joy a person has in finding lost money is used as a metaphor for the joy in heaven over a lost sinner who repents. Also see Galatians 5:22-23).
In the case of the tribes of Israel, their family sizes were all openly numbered (Numbers). With Goliath, God referenced his height (1 Samuel 17:4). In the case of Solomon, his written works were numbered (1 Kings 4:32). Also, Solomon's income was numbered (1 Kings 10:14). The number of men David slew was compared to the number Saul slew in 1 Samuel 18:7. However, David was later denied privileges because of his murderous behavior (1 Chronicles 22:8). A big number in this particular case, although it received glory from people, was bad in God's eyes. Although not specified in detail, a number is assigned to a man in Revelation 13:18. (It is the author's opinion that this is a reference to King Solomon's income, who was the wealthiest man in the world, in a spiritual way this could refer to the most powerful spirit on the earth, which would have the ability to persuade anyone who did not possess the spirit that comes from the Most High God through Jesus Christ His Son). The number of years lived by a man is often referenced throughout the Old Testament writings, and in Matthew 10:30 even the hairs of our head are all numbered by God.
So in any case it is evident that God uses numbers to describe men to varying degrees with varying purposes. God also uses relative comparisons between people. For example, Jesus described Himself as being greater than Solomon (Luke 11:31). Jesus said that the greatest love is found in self-sacrificial people (John 15:13). (Based on the entirety of the Holy Scriptures, especially verses like 1 Corinthians 3:16-17, this is not encouraging suicide but instead encourages noble acts of faith that could result in death for the Name of Jesus not for personal glory or any other reason). Samuel said that there was one better than Saul who was taking over his kingdom (1 Samuel 15:28). Jesus said some of us are given much (and thus have higher expectations) (Luke 12:48). Jesus describes some as being "poor in spirit" in Matthew 5:3.
In Daniel 5:11-12 the spirit of a man is connected to the idea of solving difficult problems. Daniel was known for being good at solving difficult problems and was rightly placed in a position of high authority. In 1 Kings 10:3 Solomon was able to answer all of the questions the Queen of Sheba asked him and the Holy Scriptures state that "nothing was hidden" from Solomon in this context (this is the original meaning of the Ancient Hebrew words used). This suggests that the opposite of having intellect is having God hide many things from us. It also suggests that intellect as we understand it is the result of direct revelation from God combined with the ability to discern His revelation to us. Our ability to discern His revelation to us could be limited by the strength of our flesh i.e. limitations in our brain and/or central nervous system and heart as it interacts with our spirit (Matthew 26:41). In Proverbs 20:29 the young and the old are differentiated from each other. In Judges 7:5 people were selected based on their behaviors. In 1 Corinthians 12:7-11 various gifts of the spirit are described and identified as coming from one source, but being given according to His will to different individuals for the profit of everyone. In Exodus 31:1-11 the ability to make various structures and garments is ascribed to God and His Spirit that He gives to the men who are assigned this specific task. In Luke 9:54-55 the original Koine Greek (obtained by looking at the interlinear on biblehub.com) of Jesus' rebuke says, "…you do not know what spirit you are…" suggesting that there are differences in ability based on the spirit that is given to a person. Samson said his supernatural strength would leave him making him as weak "…as any other man…" if he had his hair cut (Judges 16:17). Zacchaeus was noted for being short in stature compared with the people he was trying to see over (Luke 19:3). Humans are described as being worth more than many sparrows in Matthew 10:31.
More generally, measurements and details are important to God. Consider the building of the ark in the story of Noah (Genesis 6:15-16), the ark of the covenant in the days of Moses (Exodus 25:8-40, Exodus 37), the building of Solomon's temple (2 Chronicles 3-4), the making of the temple in the days of Ezekiel (Ezekiel 40-42), the measure of faith given to a man (Romans 12:3), the description and measurements of New Jerusalem in Revelation 21. Please note, the measurements given in Revelation 21 may be symbolic and not literal in nature, in contrast to the literal measurements given to the earlier prophets. However, these measurements are still given and so they are included here.
None of the measurements stated in this essay specifically refer to I.Q., so we don't know with absolute certainty that God approves of I.Q. measurement, how it is done, or the emphasis or importance that is placed on it. For example, faith seems to be a much more important quality to God than intelligence (Ephesians 2:8). The Apostle Paul also wrote in the Holy Bible that these three remain, faith, hope, and love, and the greatest of these is love. We are commanded to humble ourselves like children in order to inherit heaven and be great in heaven (Matthew 18:3-4). Children have much lower I.Q.'s than adults in most cases, and rely instead on their obedience to a higher authority, their parents, for their survival. Our eternal destination appears to be independent of the work we do here on the earth (Matthew 20:11-13, Ephesians 2:8-9), although we should be willing to do good works that God's Holy Spirit leads us to do like visiting the sick in hospitals, caring for the poor and things like these, however the details of our judgment, like how much responsibility we will have in heaven, appear to be affected by our work on the earth (Luke 19:11-27). The good works we do don't seem to really impress God all that much, however (Isaiah 64:6).
In Galatians 3:27-28 and Ephesians 4:1-6 we have a call to unity in the Spirit of Christ (for those who believe He is their Lord and who are willing to walk according to His commandments) and a marked reduction in the emphasis placed on our differences. These verses suggest basing an entire society on I.Q. testing would be faulty and no longer consistent with the gospel. I.Q. tests could be given along with many other tests (like psychological inventories that among many other things identify strengths and weaknesses in our ability to cope with stress) in order to sort out job responsibility and general expectations for the various people in our society. (Although this tends to happen naturally over time as someone who is ill-equipped to perform a job's functions normally doesn't get the job and if they do they normally don't last). So, ultimately I.Q. tests should be used in their proper context with the proper understanding of what they reveal about a person. They should not be overemphasized in their importance in evaluating a human being. They are but one of many measures of a man. They should also not be underestimated or devalued in their ability to estimate and evaluate a human being and their general intellectual ability. We should be gentle and modest in the use of I.Q. testing as we are in all things as Christians (Philippians 4:5). For those in the higher ranges of intelligence, more rigorous testing and more time spent seeking truth regarding one's intelligence is appropriate (taking many tests to determine a statistically meaningful score, for example). This is consistent with the higher expectations of those who are given much (Luke 12:48).
Apparently Goliath's great height, Samson's great strength, and Solomon's great wisdom and income didn't affect their ultimate fate on the earth. They all died. They all had to be judged by God, and the great equalizer, they all sinned. One thing we all have in common is that we all have sinned and fall short of the glory of God (Romans 3:22-24).
All this being said, Christians have a God who sets an example for us to follow (1 Corinthians 11:1). He differentiates between people with various heights, strengths, incomes, family sizes, behaviors, number slain, spirits and measures of faith. Therefore, differentiating between each other (especially for the purpose of job placement and expectations at work) based on a measure of the keenness of a person using I.Q. is not unreasonable or bad according to the Holy Bible and thus the Christian ethic by any stretch of the imagination.
Many "Christian" denominations devalue the Holy Scriptures by placing emphasis on other documents. For example, in Catholicism they have the catechism. In Mormonism they have the Book of Mormon. These additions to the Holy Scriptures and the resulting devaluation of them is unscriptural (Deuteronomy 4:2, Deuteronomy 12:32, Matthew 4:4, Revelation 22:18). In multiple denominations it has been decided to encourage the marital union of homosexuals. This practice is also unscriptural (1 Corinthians 6:9-10). This devaluation of the Holy Scriptures makes these particular denominations less likely to approve of intelligence testing or to over-value it because of a lack of knowledge of what is written in God's word or a willingness to disregard it. As previously stated, intelligence testing should be done in a gentle, modest way because we have many mitigating factors that suggest that at the very least intelligence is not the most important measurement of a man. (Binary faith in the Spirit of Christ, as manifested in the Holy Bible [either one has it or does not, the measure of it is a gift and not as important] is more important as it is directly linked to salvation, i.e. our eternal destination, whereas intelligence is not). Intelligence shouldn't be undervalued either, as it is related (it is not the only factor, however, e.g. humility is also very important — see Numbers 12:1-9) to the ability of a person to bear good fruit and thus related to the details of their eternal judgment and the responsibility they will ultimately have in heaven. Nondenominational churches and churches that hold fast to the traditions of the Holy Bible are more likely to accept the idea of I.Q. testing, as they hold a true knowledge of God. There are many confounding factors to the generalizations just made. For example, within a particular denomination and even within particular churches individuals vary widely in their beliefs and in their conformance to what is written in the Holy Bible. There are Catholic churches that allow priests to marry, for example, (this is against traditional Catholic teachings, even though the person they claim was the first pope, the Apostle Peter, was a married man), and there are churches of Christ that believe that any church that does not name themselves using the phrase "church of Christ" is not truly one of God's churches. Neither of these beliefs is consistent with what is written in the Holy Scriptures. For example, all of God's people are described as priests/holy people (1 Corinthians 1:2, 1 Peter 2:9, Revelation 1:4-6). Marriage is good (Genesis 2:18, Proverbs 18:22, 1 Corinthians 11:9). Regarding the church of Christ doctrine, when two or more people gather in the name of Jesus they have fulfilled God's expectations for a gathering that He blesses (Matthew 18:20) and the church is also referred to as the church of God (1 Corinthians 1:2).
The Holy Scriptures indicate that although God discriminates based on behavior in some circumstances, behavior is not in every case a choice that a person makes. Sometimes behavior is a person's destiny (Genesis 16:12, Isaiah 11:1-5). God is not unjust (Hebrews 6:10). He does things according to His will and it is not always within our grasp as mere mortals to understand Him (Psalm 139:6).
Here is one study that demonstrates that a higher I.Q. is inversely related to violence. Someone who stays alive in prison and doesn't get involved with violent acts is more able to bear good fruit on the earth and produce good works for the Kingdom of Heaven (Galatians 5:22-23)
Self-control is one of the fruits of the Spirit, and people with higher I.Q.'s have more of it according to science:
The most important factor that is often discussed by those involved in intelligence testing is that I.Q. tests are given honestly i.e. no bias is present in the psychometitor such that the results are skewed in some unfair way. For example, a mentally challenged patient could be given a higher score to make them feel better about themselves. Intelligence testing must be done with the Spirit of Truth, in pursuit of truth, for the purpose of revealing truth, not with bias. Of course all things should be done in love for the person we are interacting with so if a person has a very low score they should be encouraged that God loves them and saved them with His Son Jesus Christ and that they have great reason to rejoice and be glad regardless of if they lack a particular gift of the spirit at that moment in their life.
There are many studies that demonstrate a negative correlation between I.Q. and crime and a positive correlation between I.Q. and self-control. Those who die young as a result of engaging in dangerous behaviors (like breaking into someone's house, for example) have no further opportunity to bear fruit on the earth and thus are less profitable for the kingdom of heaven. The importance of love cannot be overstated. Those who have low I.Q.'s must be loved adequately to ensure that they don't engage in impulsive behavior that is going to cause themselves or others destruction. Those with high I.Q.'s must also be adequately loved as they pose a much more severe threat to society if they do choose deviant lifestyles (take, for example, those who break out of prisons and then continue in deviance). Some behaviors and personality traits are not chosen but are genetic in nature. Although the effect of environment on genetic expression is controversial, it is only reasonable to strive for the best possible environment for everyone to minimize bad behaviors. At the moment science appears to be consistent what is written in the Holy Scriptures both from the point of view of personality/behavior and intelligence and self-control. That is, science supports the idea that to a degree behavior is a choice and to a degree it is destiny, as do the Holy Scriptures. It also supports the idea that we are different in our abilities and that more can be expected from those with higher abilities.