It is not the ship in the water but the water in the ship that sinks it. So it is not the Christian in the world but the world in the Christian that constitutes the danger.
From Galatians 5:16-17: “Live by the Spirit, I say, and do not gratify the desires of the flesh. 17 For what the flesh desires is opposed to the Spirit, and what the Spirit desires is opposed to the flesh, for these are opposed to each other, to prevent you from doing what you want.
American-born John Wilbur Chapman (1959-1918) was a Christian evangelist who traveled much of the United States and the world. He was influenced by the preaching of D. L. Moody as well as the ministry of Billy Sunday.