In Luke 16:16 Jesus made an interesting comment about preaching. He contrasted preaching before the coming of John the Baptist with preaching after his advent. Here are His words:
The law and the prophets were preached until John; from this time on, God’s kingdom has been preached and everybody has been pressing into it.
In other words, preaching would take on a new aspect. Jesus had risen and was ascended to the Father’s right hand. He was ruling over His new kingdom. He had given Peter the keys to the kingdom from the heavens, and he opened the door to the new church, first for the Jews (on Pentecost), and then for the Gentiles in the house of Cornelius. He was preaching a new message—the kingdom had come!
The same emphasis may be found in the account of the transfiguration. There, Moses and Elijah (representing the law and the prophets) are said to discuss the coming exodus in which Jesus would lead men from death into life. And as these two Old Covenant figures receded into the background, God’s voice was heard to say to all coming generations, “This is My beloved Son; listen to Him!” There was to be a change from the Old era to the new in which the commandments of Jesus would be uppermost (Matthew 28:20).
The new wine could not be poured into old wineskins; the new cloth would not do as a patch sewed on a new garment. A new era with new ways had dawned. The shadows were gone; the reality had come.
Preachers should no longer preach as they once did. Now, they must interpret every passage in the Old or New Testament with New Testament eyes. They must preach the new kingdom from the heavens!