8 Again, I write a new commandment to you, which thing is true in him and in you, because the darkness is passing and the true light already shines. 9 He who says he is in the light, and hates his brother, is in the darkness until now. 10 He that loves his brother abides in light, and there is no occasion of stumbling in him.
Matthew Henry's Commentary on 1 John 2:8-10
Commentary on 1 John 2:3-11
(Read 1 John 2:3-11)
What knowledge of Christ can that be, which sees not that he is most worthy of our entire obedience? And a disobedient life shows there is neither religion nor honesty in the professor. The love of God is perfected in him that keeps his commandments. God's grace in him attains its true mark, and produces its sovereign effect as far as may be in this world, and this is man's regeneration; though never absolutely perfect here. Yet this observing Christ's commands, has holiness and excellency which, if universal, would make the earth resemble heaven itself. The command to love one another had been in force from the beginning of the world; but it might be called a new command as given to Christians. It was new in them, as their situation was new in respect of its motives, rules, and obligations. And those who walk in hatred and enmity to believers, remain in a dark state. Christian love teaches us to value our brother's soul, and to dread every thing hurtful to his purity and peace. Where spiritual darkness dwells, in mind, the judgment, and the 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 whither we are going.