Nothing perhaps affects man’s character more than the company he keeps. We catch the ways and tone of those we live and talk with, and unhappily get harm far more easily than good. Disease is infectious, but health is not.
Now if a professing Christian deliberately chooses to be intimate with those who are not friends of God and who cling to the world, his soul is sure to take harm. It is hard enough to serve Christ under any circumstances in such a world as this. But it is doubly hard to do it if we are friends of the thoughtless and ungodly. Mistakes in friendship or marriage engagements are the whole reason why some have entirely ceased to grow. "Evil communications corrupt good manners." "The friendship of the world is enmity with God" (1 Corinthians 15:33; James 4:4).