2 Peter 1:4
A girl asked me, “What is sanctification, or holiness, that people are talking so much about?” She had heard the experience testified to and talked and preached about, until I thought that, of course, she understood it. Her question surprised me, but I rallied and asked, “Have you a bad temper?”
“Oh yes,” she said, “I have a temper like a volcano.”
“Sanctification,” I replied, “is to have that bad temper taken out.” That definition set her thinking and did her good; but it was hardly accurate. If I had said,
“Sanctification is to have our sinful tempers cleansed, and the heart filled with love to God and man,” that would have done, for that is sanctification—that is holiness. It is, in our measure, to be made like God. It is to be made “partakers of the divine nature” (2 Peter 1:4).
A spark from the fire is like the fire. The tiniest twig on the giant oak, or the smallest branch of the vine, has the nature of the oak or the vine, and is in that respect like the oak or the vine. A drop of water on the end of your finger from the ocean is like the ocean—not in its size, of course, for the big ships cannot float upon it nor the big fish swim in it. But it is like the ocean in its essence, in its character, in its nature. Just so, a holy person is like God. Not that he is infinite as God is; he does not know everything; he has not all power and wisdom as God has; but he is like God in his nature. He is good and pure and loving and just, in the same way that God is.
Holiness then, is conformity to the nature of God. It is likeness to God as He is revealed in Jesus.
We are to be like Jesus in separation from the world. Jesus was in the world but He was not of the world. While He worked and associated with bad people to do them good, yet He was always separate from them in spirit.
The Apostle John, in speaking of those who expect to see Jesus in heaven says, “And every one who has this hope in him purifies himself, even as He is pure” (1 John 3:3). That is a lofty standard of purity, for there was no impurity in Jesus. He allowed no unclean habits. He indulged in no impure thoughts or desires. We are to be pure in heart and in life as He was.
We are to be like Jesus in love to God and to all men, especially to our brothers and sisters in the Lord. We are to be like Jesus by having God dwelling in us. We are to be like Him in our separation from the world, in purity, in love, and in the fullness of the Spirit. This is holiness.
Samuel Logan Brengle, The Way of Holiness