In A Treatise Concerning Religious Affections, Jonathan Edwards argues that “Gracious affections arise from the mind being enlightened rightly and spiritually to apprehend divine things.”
This is one reason that preaching is so important.
Such is the nature of man, that it is impossible his mind should be affected, unless it be by something that he apprehends, or that his mind conceives…Truly spiritual and gracious affections…arise from the enlightening of the understanding, to understand the things taught of God and Christ, in a new manner. There is a new understanding of the excellent nature of God and his wonderful perfections, some new view of Christ in his spiritual excellencies and fulness; or things are opened to him in a new manner, whereby he now understands those divine and spiritual doctrines which once were foolishness to him.
The affections, Edwards says, arise from a change in our understanding. This underlines the importance of Spirit-empowered preaching that aims at minds on their way to changing hearts.
By the way, there’s a reason Edwards is still being read today. If you’re interested in exploring Edwards, this is a good place to start.