Albert Barnes Commentary John 15:19

"If ye were of the world, the world would love its own: but because ye are not of the world, but I chose you out of the world, therefore the world hateth you." — John 15:19 (ASV)

If you were of the world. If you were motivated by the principles of the world. If, like them, you were vain, earthly, sensual, given to pleasure, wealth, and ambition, they would not oppose you.

Because you are not of the world. Because you are influenced by different principles from men of the world. You are motivated by the love of God and holiness; they by the love of sin.

I have chosen you out of the world. I have, by choosing you to be my followers, separated you from their society and placed you under the government of my holy laws.

Therefore the world hates you. A Christian may regard it as one evidence of his piety that he is hated by wicked men. Often, the most decided evidence that a man is the friend of God is given by the opposition stirred up against him by the profane, by Sabbath-breakers, and by the dissolute (1 John 3:13; John 7:7).