1 John 2:8-10
2:8 On the other hand, I am writing a new commandment to you which is true in him and in you, because the darkness is passing away and the true light is already shining.
2:9 The one who says he is in the light but still hates his fellow Christian is still in the darkness.
2:10 The one who loves his fellow Christian resides in the light, and there is no cause for stumbling in him.