The next three verses are an obvious unit. Here, we have two panels of three statements: “I write/wrote to you children/fathers/young men.” In the Bible, repetition often marks emphasis, but I think John is doing more than that here. As we look at the subtle changes he makes when he restates his reasons for writing, we learn something about how John views the Christian life.
v12. First, John addresses “dear children,” whose “sins have been forgiven on account of His name.” The word for “children” here certainly implies a young child (so “little children” is a good translation), but the primary emphasis probably is not so much on age as it is on relationship. A child is the offspring of someone. The term speaks either to the actual relationship the child enjoys with her parents or at least to the possibility (and expectation of) that relationship. We are, then, God’s “children” in virtue of the fact that our “sins have been forgiven on account of His name.” This is what all Christians have in common. It is the beginning and basis of the Christian life: our forgiveness in and for Him.