Brothers, I write no new commandment to you, but an old commandment which you had from the beginning. The old commandment is the word which you heard from the beginning.

 So, then, John means that we are assured of forgiveness because we know the character of Jesus Christ. We know that in him we see God. We see in him sacrificial love and patient mercy; therefore we know that God is like that; and, therefore. we can be sure that there is forgiveness for us. 