Paul is not suggesting that we never associate with worldly people whose lives are controlled by their fleshly desires. Just as Jesus said, we “are in the world but not of the world”. We hold ourselves to different standards. We are not to think of ourselves as “better than” nor are we to think of ourselves as “holier than” anyone. What we are to do is to separate ourselves from our Christian brothers and sisters who have chosen to live unholy lifestyles. We are as Paul puts it to “expel the wicked person from among you.” This seems harsh to us. We had rather hide behind verses such as “judge not lest you be judged” and “pull the plank out of your own eye before you point out the toothpick in your brother’s eye”. (my paraphrase) We must keep the Temple of Christ clean and holy.
1 Therefore, since we have these promises, dear friends, let us purify ourselves from everything that contaminates body and spirit, perfecting holiness out of reverence for God.—2 Cor. 7:1 NIV