saint

In Romans 16:17, Paul writes to "mark those who cause divisions contrary to the doctrine which ye have learned and avoid them." Also, in 2 John 1:10-11, the writer advises believers that "whosoever transgresseth, and abideth not in the doctrine of Christ, hath not God. He that abideth in the doctrine of Christ, he hath both the Father and the Son. If there come any unto you, and bring not this doctrine, receive him not intoyour house [οἰκίαν, residence or abode, or "inmates of the house" (family)], neither bid him God speed: for he that biddeth him God speed is partaker of his evil deeds."

http://en.m.wikipedia.org/wiki/Excommunication