Teaching children how to repent

A man may beat down the bitter fruit from an evil tree until he is weary; while the root abides in strength and vigor, the beating down of the present fruit will not hinder it from bringing forth more. (John Owen Overcoming Sin and Temptation p76)

It is never too early to teach a child how to battle with sin. Sin is with them from birth, and bears fruit for death. A parent may very easily either try to beat the bitter fruit from the tree of a child, or encourage the child to do so, without realizing that the root is untouched. The only way to address the root of sin is through the gospel because sin arises out of our nature, not merely our circumstances or personality (although these certainly play a role). The gospel addresses not only our sinful behavior, but our sinful nature from which all those behaviors arise.

It is to be feared that very many have little knowledge of the main enemy that they carry about with them in their bosoms. (ibid. p76)

The key to teaching children how to repent is to show them that their sin nature is their own worst enemy. If we teach them this, they'll learn not to play the blame game, but instead to pray to God for mercy and deliverance - and they will find it!