Christ prayed for his disciples, "I pray not that thou shouldest take them out of the world, but that thou shouldest keep them from the evil." (John 17:15) I have given them thy word; and the world hath hated them, because they are not of the world." (John 17:14)
While Christians are to be in the world, they are not to be of the world. In order to be a saving power, they must separate from all worldliness. As oil does not mix with water, so they are not to mix with that which God condemns. They must keep themselves "unspotted from the world;" for they can not touch that which is unclean, and remain unpolluted. The truth as it is in Jesus must sanctify their souls. Its deep, living principles must preside over thought and word and action.
On every hand there is that which would tempt the Christian to forsake the narrow way; but those who would perfect a character fit for eternity must take the will of God as their standard, separating entirely from everything that is displeasing to him. Thousands are betrayed into sin because they leave the citadel of the heart unguarded. They become engrossed with the cares of this world, and true godliness is driven from their hearts. They rush eagerly into speculation, seeking to accumulate more of this world's treasure. Thus they place themselves where it is impossible for them to advance in the Christian life. "Be ye therefore sober, and watch unto prayer." (1 Peter 4:7) And while you pray, strive earnestly to guard your heart from all pollution; for prayer without effort is a solemn mockery. ST, December 17, 1896 par. 1-3
Jesus took the nature of humanity, in order to reveal to man a pure, unselfish love, to teach us how to love one another. Hvn 74
And what do you benefit if you gain the whole world but lose your own soul? Mark 8:36 (New Living Translation)