Preach so that we can taste the truth!

When Tim Keller urges pastors to preach to the hearts of their hearers so that God's Word can do its work amongst God's people, he often quotes Jonathan Edwards to underline that the purpose of a sermon is not just to make the truth clear but to make the truth real. In Edwards' sermon, A Divine and Supernatural Light, Edwards uses honey as an illustration to make his point:

Thus there is a difference between having an opinion, that God is holy and gracious, and having a sense of the loveliness and beauty of that holiness and grace. There is a difference between having a rational judgment that honey is sweet, and having a sense of its sweetness. A man may have the former, that knows not how honey tastes; but a man cannot have the latter unless he has an idea of the taste of honey in his mind. So there is a difference between believing that a person is beautiful, and having a sense of his beauty. The former may be obtained by hearsay, but the latter only by seeing the countenance. There is a wide difference between mere speculative rational judging any thing to be excellent, and having a sense of its sweetness and beauty. The former rests only in the head, speculation only is concerned in it; but the heart is concerned in the latter. When the heart is sensible of the beauty and amiableness of a thing, it necessarily feels pleasure in the apprehension. It is implied in a person's being heartily sensible of the loveliness of a thing, that the idea of it is sweet and pleasant to his soul; which is a far different thing from having a rational opinion that it is excellent.