The term “the age of accountability” is not found in the Bible. But just because a term is not found in the Bible, does not mean that we cannot use that term. If the term accurately describes something that is in the Bible, there is nothing wrong with using that term.
The term “the age of accountability” is a term that we, Christians, use to describe the point in a person's life when they become accountable to God for either accepting or rejecting Christ as their personal Lord and Savior. This is normally around the age of 12.
In Romans, chapter 7, verses 9–11, the apostle Paul said,
9 For I was alive without the Law once: but when the commandment came, sin revived, and I died.
10 And the commandment, which was ordained to life, I found to be unto death.
11 For sin, taking occasion by the commandment, deceived me, and by it slew me.
Paul said that there was a time in his life that he was alive, but when the commandment came, sin revived, took occasion by the commandment, and killed him. This could only be talking about spiritual death.
There are only three types of death. There is physical death, where your spirit and soul leave your body and your body becomes lifeless. There is spiritual death, which is when you are separated from God. And there is the second death, which only sinners, non-Christians, will experience when they will get thrown into the lake of fire, Gehenna, on judgment day.
Judgment day has not come yet, so no one has experienced the second death yet. It could not be talking about physical death, because when Paul experienced this death that this Scripture speaks about, he was still physically alive. Therefore, it must be referring to spiritual death.
When a person comes into existence at conception, a zygote, or zygocyte, is formed by the union of two gametes: the sperm cell, or male gamete, and the ovum, or female gamete. It is at this point that God creates this person—spirit, soul, and body. This person never existed before this point. God does not have spirits and souls of babies in Heaven that He implants into zygotes at conception. God creates each person at conception. This is one of the scientific and natural laws that God set up when He created the universe and man—that when a sperm cell, or male gamete, comes into union with an ovum, or female gamete (sometimes called an “egg”), a human being, created by God, comes into existence.
When God creates a person, they are spiritually alive. They do not have a sin nature on the inside of them. How could they? They have just been created by God. God doesn't create sin or sinful people. Everything that God creates is pure. The idea of man being born with “original sin” or a “sin nature” is not Biblical.
This is what the apostle Paul was saying in this Scripture in Romans 7. He was saying that he was spiritually alive from conception on, until “the commandment came.” The phrase “the commandment came” is referring to the coming of the realization, the comprehension, the understanding, the consciousness, the awareness, the knowing of what is right and what is wrong (sin), and the consequences thereof, according to the Law, the commandments of God. In verse 7 Paul said, “I had not known sin, but by the Law: for I had not known lust, except the Law had said, ‘Thou shalt not covet.’”
Once this comprehension, this understanding, this knowing of sin and what is right and wrong, and the consequences thereof, according to the Law of God comes, a person dies spiritually if they haven't already been born again. This would happen at different times for different people, but it would usually happen about the age of 12. In some cases, because a person may be born mentally incompetent and never gets to the point of mental competence, the person NEVER dies spiritually. In other words, some people, like babies, and little children, and people who never get to the point of mental competence, NEVER die spiritually, and thus, when they physically die without being born again, they still go to Heaven because they are still spiritually alive.
Our Baptist brethren say it this way, “As soon as they are capable of moral action, they become transgressors and are under condemnation” (Baptist Faith and Message, Article 3). This would imply that if a person never reached a point where they were “capable of moral action” they would never die spiritually and become a transgressor under condemnation.
Our Baptist brethren also say that since water baptism is “an outward sign of an inward grace” that is to take place after a person is born again, and we do not have any accounts in the New Testament of small children or babies being water baptized, that this would indicate that small children and babies have not yet reached this moral accountability age or moral discernment age or moral competency age, and so would still go to Heaven if they died without being born again.
But how did we, Christians, come up with this idea that a person reaches this “age of accountability” at about the age of 12?
Part of it is taken from Christians' personal experiences, but mostly it is taken from the Word of God in Luke, chapter 2, verses 40–50.
As far as personal experiences go, I remember Kenneth E. Hagin, when he was alive, saying that he remembered when he died spiritually at the age of 12. He got born again when he was 15.
I, myself, can remember the moment when I died spiritually. I, also, was 12 years old. I was in the 7th grade. I was in junior high school walking north down the hall past the assistant principal's office between classes. I remember what I was thinking, and I knew that something had happened to me, but I didn't know what it was. (Years later, when I learned about this, I realized that that was the point in time when I died spiritually.) I got born again a few months later, just after my 13th birthday.
Luke 2:41–42 says, in referring to Jesus,
“Now His parents went to Jerusalem every year at the Feast of the Passover. And when He was twelve years old, they went up to Jerusalem after the custom of the Feast.”
Jesus is mentioned in the Scriptures when He was conceived in the womb of Mary in Nazareth, Galilee. He is mentioned when He was born in Bethlehem, Judea and when He was circumcised when He was eight days old. He is mentioned when He was in Jerusalem when He was just over 40 days old when Mary was offering her sacrifice after the days of her purification were completed.
He is then mentioned when He is about 16 months old when the wise men came to visit Him at His home in Nazareth, Galilee and when He went to Egypt with His parents. He is mentioned when He returned home from Egypt with His parents when He was about 1½ years old.
He is next mentioned when He was 12½ years old at the Feast of the Passover in Jerusalem, Judea. He is not mentioned again until He entered the ministry at the age of 30.
The fact that Jesus is mentioned when He was 12 years old must have some significance. Aside from when He had first learned to walk and talk when the wise men came to see Him at His home in Nazareth, Galilee when He was about 16 months old and when He went to Egypt, this is the only time in His childhood that He is mentioned in the Scriptures since the time surrounding His birth.
Every year, at the time of the Feast of the Passover, which was around the third week of spring, Jesus' parents, along with Jesus (and His younger brothers and sisters when they had been born), came to Jerusalem. Jesus always went back home to Nazareth with His parents every year until the year when He was 12 years old.
But the year that Jesus was 12, He stayed behind in Jerusalem without telling His parents. His parents assumed that He was traveling back home to Nazareth with some relatives or friends of theirs, and that they would see Him along the way. But after traveling for a day, and not seeing Him, they tried to find Him among their relatives and friends. And when they couldn't find Him, they went back to Jerusalem. After three days of searching, they found Him in the temple having discussions with the doctors of the Law.
When Joseph and Mary asked Jesus why He had thus dealt with them, Jesus said, “How is it that ye sought me? Knew ye not that I must be about my Father's business?” (verse 49).
Jesus' attitude was, “I'm 12 years old now. Why were you looking for me? Didn't you know that because I am now 12, I must be about my Father's business?”
So based on this passage of Scripture, we see a definite change of attitude and responsibility and accountability once a person reaches the age of 12.
This is also where the Jewish ideas of “bar mitzvah” and “bat mitzvah” come from. The Jewish people have a ceremony for boys (bar mitzvah) and girls (bat mitzvah) around this age that signifies—among other things—that they are now accountable for their actions.
In other words, these are the terms that Jewish people use (“bar mitzvah” for boys, and “bat mitzvah” for girls) to say that a child has now reached “the age of accountability.”
“Mitzvah” is the Hebrew word for “commandment.” What the Jewish people are saying, is that at about the age of 12, “the commandment comes.” This is the same thing that the apostle Paul—who was Jewish—said in Romans 7:9.
Once a person reaches this “age of accountability”—whatever age it may be for a given person—the person dies spiritually, becomes separated from God, if they have not already been born again. If a person is born again before reaching this age, then they never experience a time in their life when they are spiritually dead. However, if a person is not born again before reaching this point in their life, then they die spiritually. And if they were to die physically anytime after this point, before being born again, they would go to Hell as a sinner.
Therefore, it would behoove a person to get born again as early in life as possible. Jesus said in John 3:3,
“Except a man be born again, he cannot see the kingdom of God.”