The mingling of that which is of God with that which is of man is a special form of evil, and a very effectual engine, in Satan’s hand, for marring the testimony of Christ on the earth. This mingling may frequently wear the appearance of something very desirable; it may often look like a wider promulgation of that which is of God—a fuller and a more vigorous outgoing of a divine influence—a something to be rejoiced in rather than to be deplored: but our judgment as to this will depend entirely upon the point of view from which we contemplate it. If we look at it in the light of God’s presence, we cannot possibly imagine that an advantage is gained when the people of God mingle themselves with the children of this world, or when the truth of God is corrupted by human admixture. Such is not the divine method of promulgating truth, or of advancing the interests of those who ought to occupy the place of witnesses for Him on the earth. Separation from all evil is God’s principle; and this principle can never be infringed without serious damage to the truth. …Satan’s first effort was to frustrate God’s purpose by putting the holy seed to death; and when that failed, he sought to gain his end by corrupting it.

—C. H. Mackintosh , Notes on Genesis