Mark 2:22

In order to fully benefit from the New Testament and the message of salvation by faith in Jesus Christ alone we must let go of legalism and the traditions of man. God wants to work a marvelous thing in our future but it only comes by putting our complete trust in Him and in the salvation only He can give.

The comparison implies that the newness of His message, and of the new covenant to follow, cannot fit into the old molds of Judaism. The Old Testament was preparation for the New Testament.

Mark 2:22                                                                                   

22 And no one puts new wine into old wineskins; or else the new wine bursts the wineskins, the wine is spilled, and the wineskins are ruined. But new wine must be put into new wineskins.”