And pray ye without ceasing, in behalf of other men. For there is in them hope of repentance that they may attain to God. See then, that they be instructed by your works if in no other way. Be ye meek in response to their wrath, humble in opposition to their boasting. To their blasphemies, return your prayers, in contrast to their error, be ye steadfast in the faith, and for their cruelty, manifest your gentleness.
-St. Ignatius of Antioch, Letter to the Ephesians.

I am deeply grieved, brethren for (Valens) and his wife; to whom may the Lord grant true repentance! And be ye then moderate in regard to this matter, and "do not count such as enemies" but call them back as suffering and straying members, that ye may save your whole body. For by so acting, ye shall edify yourselves.
-From the Epistle of Saint Polycarp to the Phillipians

Shunning, as done in some communities goes against this directive from Polycarp. "Do not count such as enemies," in quotes by Polycarp, shows that this was taught even prior to this early time. We are to swallow our own pride and use these difficult situations as an offering to God for our own humility and others' conversion.