1 John 2:7 WEB

⁵  But whoever keeps his word, God's love has most assuredly been perfected in him. This is how we know that we are in him:

⁶  he who says he remains in him ought himself also to walk just like he walked.

⁷  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.

⁸  Again, I write a new commandment to you, which is true in him and in you; because the darkness is passing away, and the true light already shines.

⁹  He who says he is in the light and hates his brother, is in the darkness even until now.