Paul's letter to Titus is a short epistle telling Titus (ordained as the first bishop of the Church of the Cretians) how to pick good leaders. Faithfulness to the Gospel is especially important, says Paul, because the Cretians are a bunch of lazy, lying no-gooders. (Titus 1:6-9, 2:1-5) Paul says Christians should live by a high standard, being obediant to their rulers, peaceful, and avoiding arguments about the law. He also recommends a "third strike" for troublemakers who refused to listen and therefore should be shunned by other Christians.
"A man that is an heretic after the first and second admonition reject; Knowing that he that is such is subverted, and sinneth, being condemned of himself." -- Titus 3:10-11
Hmn, really? Should a good Christian ever give up on someone? I don't know how I feel about that idea. What about the whole "do not judge lest ye be judged," and "who will cast the first stone" philosophy?