Charles Spurgeon Commentary 1 John 2:8-10

"Again, a new commandment write I unto you, which thing is true in him and in you; because the darkness is passing away, and the true light already shineth. He that saith he is in the light and hateth his brother, is in the darkness even until now. He that loveth his brother abideth in the light, and there is no occasion of stumbling in him." — 1 John 2:8-10 (ASV)

Again, a new commandment I write unto you, which thing is true in him and in you: because the darkness is past, and the true light now shineth. He that saith he is in the light, and hateth his brother, is in darkness even until now. He that loveth his brother abideth in the light, and there is none occasion of stumbling in him.

Love is the great and sure way of abiding in the light, abiding in Christ.