Q. I am searching scripture looking for something that tells me that the children under the age of accountability will also be taken in the rapture. A friend asked me this and I told her that yes they would be removed at the rapture but could not back-up my statement with scripture that actually spells that out.
A. The idea that all children under the age of accountability will be taken in the rapture comes from two places. The first is Matt. 18. Verse 3 says we have to change and become like little children in order to enter the kingdom of heaven. That means children are the model to which all believers have to conform in order to enter the kingdom. Verse 10 says that all children have an angel in constant contact with the Father. This leads us to conclude that all children belong to God.
The second place is Romans 7:9. Here, Paul wrote about being alive apart from the law, but then the commandment came, sin sprang to life and he died. Since he was still physically alive he had to be talking about spiritual death. So he was saying that before the age of accountability, he had eternal life. But as soon as he reached the age where he became accountable for his sins, he was scheduled for death and needed to find a way to regain eternal life.
Put it all together and it appears that all children are born with eternal life. They belong to God and and their sins are not counted against them. The way adults become like them so we can have eternal life is to be born again, because then we become a child of God again (John 1:12-13) and our sins are no longer counted against us (Romans 7:18-20). This makes all children and born again adults equally qualified for the rapture.