Matthew Henry Commentary 1 John 2:3-11

"And hereby we know that we know him, if we keep his commandments. He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him; but whoso keepeth his word, in him verily hath the love of God been perfected. Hereby we know that we are in him: he that saith he abideth in him ought himself also to walk even as he walked. Beloved, no new commandment write I unto you, but an old commandment which ye had from the beginning: the old commandment is the word which ye heard. 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. But he that hateth his brother is in the darkness, and walketh in the darkness, and knoweth not whither he goeth, because the darkness hath blinded his eyes." — 1 John 2:3-11 (ASV)

What knowledge of Christ can that be which does not see that He is most worthy of our entire obedience? A disobedient life shows there is neither religion nor honesty in the professing Christian. The love of God is perfected in the one who keeps His commandments. God's grace in such a person attains its true mark, and produces its sovereign effect as far as possible in this world, and this is human regeneration; though it is never absolutely perfect here.

Yet, observing Christ's commands has a holiness and excellence that, if universal, would make the earth resemble heaven itself. The command to love one another had been in force since the beginning of the world; but it might be called a new command as given to Christians. It was new for them, as their situation was new regarding its motives, rules, and obligations.

And those who walk in hatred and enmity toward believers remain in a dark state. Christian love teaches us to value our brother's soul and to dread everything hurtful to his purity and peace. Where spiritual darkness dwells, the mind, judgment, and conscience will be darkened and will mistake the way to heavenly life. These things demand serious self-examination; and earnest prayer that God would show us what we are and where we are going.