My little children, these things I write to you, so that you may not sin. And if anyone sins, we have an Advocate with the Father, Jesus Christ the righteous.
And He Himself is the propitiation for our sins, and not for ours only but also for the whole world.
Now by this we know that we know Him, if we keep His commandments.
He who says, "I know Him," and does not keep His commandments, is a liar, and the truth is not in him.
But whoever keeps His word, truly the love of God is perfected in him. By this we know that we are in Him.
He who says he abides in Him ought himself also to walk just as He walked.
Brethren, I write no new commandment to you, but an old commandment which you have had from the beginning. The old commandment is the word which you heard from the beginning.
References for 1 John 2:7