MY SON TIMOTHY, the saying is sure and worthy of full acceptance. For this purpose we both work hard and are rejected, because we have placed our hope in the living God, Who is the Savior of all people, especially of those who believe. These are the things you must command and teach. Let no one despise your youth, but be an example to the believers in speech and your way of life, in love, in spirit, in faith, and in purity. Until I arrive, devote yourself to the public reading of Scripture, encouragement, and teaching. Do not neglect the gift that is in you, which was given to you by prophecy with the laying on of hands by the presbyters. Be attentive to these things, dedicate yourself to them completely, so that all may see your progress.
Saint John Chrysostom talking about things that must be commanded and things that must be taught, says,
In some cases it is necessary to command, in others to teach; if therefore you command in those cases where teaching is required, you will become ridiculous. Again, if you teach where you should command, you are exposed to the same reproach. For instance, it is not proper to teach a man not to be wicked, but to command; to forbid it with all authority. Not to profess [other beliefs], should be a command; but teaching is required, when you would lead people to part with their possessions, to profess virginity, or when you would discourse of faith. Therefore, Paul mentions both: command and teach. When a person uses amulets, or does anything of that kind, knowing it to be wrong, he requires only a command; but he who does it ignorantly, is to be taught his error.