This verse is about the primacy of preaching: so we preach and so you believed. There is not to be any emotional manipulation in the proclamation of the gospel. Some people, they advocate drama, and so-called Christian films, and all kinds of things to communicate the gospel, but that is emotional manipulation. That cannot result in true converts. Some people try only intellectual means, and they put all their attention and effort into apologetics to try to convince people intellectually concerning the truth of the gospel. Apologetics are very useful and helpful and very comforting, but they can never save. The essential proclamation of the gospel: these are doctrines and truths to be proclaimed, explained, with the preacher aiming at the understanding and the will together. And people must be appealed to. So yes, you can persuade them, but there must be a clear presentation of the gospel. That is the ordinance of God. Here it is: preaching. ‘So we preach [herald, proclaim] and so ye believed.’ These truths must be believed with all our hearts in order to be saved. Of course, if you truly believe the gospel, then you obey too – that is to say, you obey its command to repent and to yield your life to Christ and to trust him – but that is because you believe. Understanding by the power of the Spirit is vital. It is part of the illuminating, regenerating work of God.