God in his wisdom hath so made the outward world, that it is a strange and wonderful picture of the inner world. Nature has an analogy with grace. The wonders that God does in the heart of man, each of them finds a parallel, a picture, a metaphor, an illustration, in the wonders which God performs in providence. It is the duty of the minister always to look for these analogies. Our Saviour did so. He is the model preacher: his preaching was made up of parables, pictures from the outer world, accommodated to teach great and mighty truths. And so is man's mind constituted that we can always see a thing better through a picture than anyhow else. If you tell a man a simple truth, he does not see it nearly so well as if you told it to him in an illustration. If I should attempt to describe the flight of a soul from sin to Christ, you would not see it one half so readily as if I should picture John Bunyan's pilgrim running out of the city of destruction, with his fingers in his ears, and hastening with all his might to the wicket gate. There is something tangible in a picture, a something which our poor flesh and blood can lay hold of; and therefore the mind, grasping through the flesh and the blood, is able to understand the idea, and to appropriate it. Hence the necessity and usefulness of the minister always endeavonring to illustrate his sermon, and to make his discourse as much as possible like the parables of Jesus Christ.Read the sermon in its entirety HERE. By the way, John MacArthur has adopted this same philosophy, usually employing the OT as illustrative material for the NT truth.
Now, there are very few minds that can make parables. The fact is, I do not know of but one good allegory in the English language, and that is, the "Pilgrim's Progress in Parables, pictures, and analogies are not so easy as some think; most men can understand them, but few can create them. Happy for us who are ministers of Christ, we have no great trouble about this matter; we have not to make parables; they are made for us. I believe that Old Testament history has for one of its designs the furnishing of the Christian minister with illustrations; so that a truth which I find in the New Testament in its naked form taught me as a doctrine, I find in the Old Testament cast into a parable. And so would we use this most excellent ancient book, the Old Testament, as an illustration of the New, and as a means of explaining to our minds the truth that is taught to us in a more doctrinal form in the New Testament.
Viewing the world through the window of the Historic, Reformed, Baptist Faith.