But as for you, brethren, do not grow weary in doing good. And if anyone does not obey our word in this epistle, note that person and do not keep company with him, that he may be ashamed. Yet do not count him as an enemy, but admonish him as a brother. Now may the Lord of peace Himself give you peace always in every way. The Lord be with you all. (2 Thessalonians 3:13-16)
St Paul encourages us to not to keep company with those who claim to be Christian but then who don’t attempt to follow the teachings of the New Testament. However, he also admonishes us not to treat these straying Christians as enemies, but as brothers and sisters who have lost their way (Paul actually does this in his confrontation of Peter as he reports in his letter to the Galatians, 2:11-16). We are not to hate them, but to love them in order that we might obey Christ and be at peace with those around us.
Paul also encourages us not to lose heart and grow weary in well doing just because life is difficult. He wants us to strive to follow Christ in as many ways as we can – not just in prayer, but in practicing all the virtues as well. As we read from the 6th Century anonymous monk now called Pseudo-Macarius who inspires us to imitate Christ and to obey His gospel commandments:
If a person pushes himself to attain prayer alone, when he has none, in order to attain its grace, without striving earnestly for meekness and humility and charity and all the other commandments of the Lord, neither taking pains nor struggling and battling to succeed in these as far as his choice and free will go, he may at times be given a grace of prayer with some degree of repose and pleasure from the Spirit according as he asks. But he has the same traits he had before. He has no meekness, because he did not seek it with effort and he did not prepare himself beforehand to become meek. He has no humility, since he did not ask for it and did not push himself to have it. He has no charity toward all men, because he was not concerned with it and did not strive for it in his asking for the gift of prayer. And in doing his work, he has no faith or trust in God, since he did not know that he was without it. And he did not take the pains to seek from the Lord for himself to have a firm faith and an authentic trust.
For just as he forces himself to prayer, even when unwilling, so everyone must push himself likewise to trust, so also to humility, so to charity, so to meekness, sincerity, and simplicity, so ‘unto every patience and long-suffering with joy’ (Colossians 1:11), so also to regard himself as little and to consider himself as poor and the least of all. He strives not to speak without profit, but always to be concerned to speak the things of God with mouth and heart. He is attentive not to become angry and loud-mouthed according to the saying, ‘Let all bitterness and anger and clamoring be put away from you, with all malice’ (Ephesians 4: 31). He strives to live according to all the ways of the Lord, in the practice of virtue and good and noble conduct, to possess all manifestations of goodness, of humility, of meekness, never being proud and high-minded and puffed up and never to speak against any one. (THE FIFTY SPIRITUAL HOMILIES, pp 147-148)