Slaves belonging to Christian masters must not despise them, for they are believers too. Instead, they are to serve them even better, because those who benefit from their work are believers whom they love. You must teach and preach these things.
to preach the message, to insist upon proclaiming it (whether the time is right or not), to convince, reproach, and encourage, as you teach with all patience.
This is a true saying. I want you to give special emphasis to these matters, so that those who believe in God may be concerned with giving their time to doing good deeds, which are good and useful for everyone.