A friend sent me an email asking if I believed in an "age of accountability" for children, saying that it didn't seem to be in the Bible anywhere. Here is my response...
The first part of my answer is not pleasant to think about (even to me), but hang with me, because the second part gets a lot better and shows the "silver lining in the cloud."
I do not believe in an “age of accountability,” first because it's not in the Bible, as you pointed out, but also because I believe that all humans, except for the virgin-born Christ, became sinful and separated from God when Adam fell in the garden. “Just as through one man sin entered into the world, and death through sin, and so death spread to all men, because all sinned” (Rom. 5:12, also 1 Cor. 15:21-22).
This is called “covenantal headship” or “federal representation”… the word “Adam” in Hebrew is the same word for “man” or “mankind,” and he and Eve were mankind at the time, so their penalty of death (primarily spiritual, as explained above, but with physical death beginning as a result) passed down to all of us at conception, because we are “in Adam.” “Behold, I was brought forth in iniquity, and in sin my mother conceived me” (Psa. 51:5, also 58:3).
We do not become sinners because we start sinning at some point in our childhood; we sin because we are already sinners by nature. “You were dead in your trespasses and sins…and were by nature children of wrath, even as the rest” (Eph. 2:1-3)
That’s why we don’t have to teach children (cute as they are) to say “NO!” or “MINE!” Instead we must teach them to obey and share. They are born sinners, and therefore are eligible for the just punishment that sin deserves. God may choose to save young children who die, but it would not be based on their "innocence," but merely because of His grace and mercy in Christ. (The Bible doesn't speak clearly to that issue of young children who die, which is probably intentional because if it did, people throughout history would have killed their children to ensure them a place in heaven, or grieved hopelessly if they were known to be in hell. We must simply trust that "the Judge of the earth will do right" as Abraham said in Genesis 18:25, and leave the "secret things" to God as Moses said in Deuteronomy 29:29.)
But back to the principle of representation (or "original sin"): it is admittedly a tough pill to swallow. “I became sinful and separated from God because of what someone else did?! That seems unfair!!” But I have come to accept it because it’s clearly taught in the Bible, and even more because I’ve realized it’s the only way I can be saved from my sins and guaranteed a place in heaven forever. If God didn’t relate to us through this principle, then Jesus couldn’t have lived a perfect life and died on my behalf… but as it is, I can receive all His righteousness and be forgiven of all my sins because of what someone else did. So my destiny is not dependent upon my performance, but on His.
If I had to “stand on my own” before God, like Adam in the garden, I’m sure I would eventually fall like he did... if not right away! And that could happen even if I somehow managed to get to heaven. Who’s to say that after a week, a year, a hundred or a thousand years in, I would not blow it like Satan and Adam did and be cast out? I would never know if I was there for good! But because I am “in Christ” (arguably the two most important words in the Bible), I know that God relates to me through this representative and I am safe forever. How long will Jesus be perfect? Forever. How long will Jesus be loved by His father? Forever. How long will Jesus reign in the new heavens and new earth? Forever. So I will enjoy all those things just as long as He does, because by faith I am in union with Him!
This is the good news (or “gospel”) of grace, which unfortunately many people don’t grasp yet, even many Christians (I was one of those for a long time). It’s been put well this way: “In myself I am more sinful and undeserving than I ever feared to admit, but in Christ I am more loved and accepted than I ever dared to hope.” And that understanding of grace helps us to relate to others in the same way, loving them fully and continually even when they don’t deserve it.