“Complicity with error will take from the best of men the power to enter any successful protest against it … Fellowship with known and vital error is participation in sin … As soon as I saw, or thought I saw, that error had become firmly established, I did not deliberate, but quitted the body at once. Since then my counsel has been ‘Come out from among them.’ I have felt that no protest could be equal to that of distinct separation from known evil … That I might not stultify my testimony I have cut myself clear of those who err from the faith, and even from those who associate with them.”
— C. H. Spurgeon
2 Corinthians 6:17 Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you,
Romans 16:17 Now I beseech you, brethren, mark them which cause divisions and offences contrary to the doctrine which ye have learned; and avoid them.
2 Thessalonians 3:14 And if any man obey not our word by this epistle, note that man, and have no company with him, that he may be ashamed.