All things which are written about Me in the Law of Moses and the Prophets and the Psalms must be fulfilled. – Luke 24:44
The term typology refers to the study of the many pictures in the Old Testament that depict New Testament truths. New Testament realities were prefigured in the Old Testament, so in this way, the New Testament is the clarification of the Old. The pictures in the Old Testament were painted in anticipation of what God was going to do when His full revelation was demonstrated in the New Testament.
If we look at the story of the disciples on the Emmaus Road (Luke 24), we see that in order to explain Himself to the two confused followers, Jesus went back to Moses and the prophets—the Old Testament (verse 27). Jesus was explaining Himself through events that took place hundreds of years earlier because these events pictured Him. They anticipated His coming; they looked forward to Him.
C.S. Lewis explained that Jesus was either a liar, a lunatic, or the Lord. If you eavesdropped on His conversation with the disciples on the Emmaus Road, you might think He was a liar. How could the Old Testament be talking about Him? He was only 30 or so years old when this took place. You might think He was a lunatic because He thought people in Old Testament times were talking about Him. Or you’d have to think He is Lord and everything in Scripture truly is about Him. All the Old Testament points to Jesus: “Do not think I came to abolish the Law or the Prophets; I did not come to abolish but to fulfill” (Matthew 5:17).