The following is a letter from the Church Father, Athanasius (ca. AD 298-373), famous for standing against the Arian heresy in the First Council of Nicea (AD 325), a battle which he carried on throughout his ministry.
As a churchman in an age quite different from our own, there are aspects of Athanasius’ views that would not be accepted by fundamentalist Baptists. But when you read this letter, you will catch a spirit that resonates with us.
I thank the Lord who hath given to you to believe in Him, that ye too may have with the saints eternal life. But because there are certain persons who hold with Arius and go about the monasteries with no other object save that under color of visiting you, and returning from us they may deceive the simple; whereas there are certain who, while they affirm that they do not hold with Arius, yet compromise themselves and worship with his party; I have been compelled, at the instance of certain most sincere brethren, to write at once in order that keeping faithfully and without guile the pious faith which God’s grace works in you, you may not give occasion of scandal to the brethren.
For when any sees you, the faithful in Christ, associate and communicate with such people, [or worshipping along with them], certainly they will think it a matter of indifference and will fall into the mire of irreligion.
Lest, then, this should happen, be pleased, beloved, to shun those who hold the impiety [of Arius], and moreover to avoid those who, while they pretend not to hold with Arius, yet worship with the impious. And we are specially bound to fly from the communion of men whose opinions we hold in execration. [If then any come to you, and, as blessed John says, brings with him right doctrine, say to him, All hail, and receive such an one as a brother.] But if any pretend that he confesses the right faith, but appear to communicate with those others, exhort him to abstain from such communion, and if he promise to do so, treat him as a brother, but if he persist in a contentious spirit, him avoid.
[I might greatly lengthen my letter, adding from the divine Scriptures the outline of this teaching. But since, being wise men, you can anticipate those who write, and rather, being intent upon self-denial, are fit to instruct others also, I have dictated a short letter, as from one loving friend to others, in the confidence] that living as you do you will preserve a pure and sincere faith, and that those persons, seeing that you do not join with them in worship, will derive benefit, fearing lest they be accounted as impious, and as those who hold with them.
Athanasius, “The Festal Letters, Personal Letters, Letter 53” Philip Schaff, ed., vol. 4, The Post-Nicene Fathers, electronic ed., electronic ed. (Garland, TX: Galaxie Software, 2000). [Paragraphs added for ease of reading. Emphasis added.]
HT: Brian Collins