1 John 2:4-7

4He that says, I know him, and does not keep his commandments, is a liar, and the truth is not in him;

5but whoever keeps his word, in him verily the love of 1God is perfected. Hereby we know that we are in him.

6He that says he abides in him ought, even as he walked, himself also [so] to walk.

7Beloved, I write no new commandment to you, but an old commandment, which ye have had from the beginning. The old commandment is the word which ye heard.