Associating with others

How does a confessional Christian relate to a fellow Christian of that same church who was going to be excommunicated because of one's impenitence, but then asked to be released from the congregation instead, which the church did with a letter of admonition? This person shortly thereafter claimed to have left the Christian religion. In regard to Matthew 18, 2 Thess. 3, and 1Cor. 5, does a Christian continue not to associate with the impenitent brother who has left the Christian faith, or, now that the person has claimed not to be a Christian, does the Christian now associate with them and resume a relationship?

In regard to either scenario, the concern about “associating” is that, by our attitudes and actions, we somehow mistakenly lead an impenitent person to downplay impenitence and unbelief, and conclude that what they did was not so bad after all.

If we completely cut off contact from such people, we also remove godly influence and Christian testimony from their lives. (And it is only through the word of God through which God works to change hearts and lives.) Christians like you, then, strive to maintain a balance between testifying to the seriousness of sin, impenitence and unbelief, and living a life of Christian love in your interaction with others. God bless your balancing of these testimonies!