In a remarkable little comment on Paul’s first letter to the Corinthians, John Calvin made these remarks:
Imitators of me…Paul had [in the previous chapter] there brought forward his own example in confirmation of his doctrine. Now, in order that the Corinthians may understand that this would be becoming in them, he exhorts them to imitate what he had done, even as he had imitated Christ.
Here there are two things to be observed—first, that he prescribes nothing to others that he had not first practised himself; and, secondly, that he directs himself and others to Christ as the only pattern of right acting. For while it is the part of a good teacher to enjoin nothing in words but what he is prepared to practise in action, he must not, at the same time, be so austere, as straightway to require from others everything that he does himself, as is the manner of the superstitious. For everything that they contract a liking for they impose also upon others, and would have their own example to be held absolutely as a rule. The world is also, of its own accord, inclined to a misdirected imitation, (κακοζηλίαν)1 and, after the manner of apes, strive to copy whatever they see done by persons of great influence. We see, however, how many evils have been introduced into the Church by this absurd desire of imitating all the actions of the saints, without exception. Let us, therefore, maintain so much the more carefully this doctrine of Paul—that we are to follow men, provided they take Christ as their grand model, (πρωτότυπον,) that the examples of the saints may not tend to lead us away from Christ, but rather to direct us to him.
- Good teachers prescribe nothing that they do not practice themslves.
- They direct others to the ideal, not just to their own practice.
- Good teachers must not require others to immediately become exactly like themselves for they might fall short of the ideal or be expecting unrealistic transformation.
 John Calvin and John Pringle, Commentaries on the Epistles of Paul the Apostle to the Corinthians, vol. 1 (Bellingham, WA: Logos Bible Software, 2010), 349–350.