I certainly teach that the whole Bible is about Jesus. The Bible, on the whole, is the story of how a holy God relates to a sinful and fallen people. Jesus is at the center of that story. You’ve heard all this before.
The question I heard raised this morning is “Can a person get saved only reading the Old Testament?” II Timothy 3 tells us that all scripture is given by the inspiration of God. Obviously the New Testament is God-given, and we need to read and study it. If the Old Testament was sufficient, why would God give us another? But still, if the gospel is all over the Bible, is there enough there to lead a person to Christ? And I say, yes it is possible.
When the Ethiopian eunuch was reading Isaiah, Philip took those passages and preached Jesus Christ. Isaiah 53 is a vivid depiction of the crucifixion. Reading of the crucifixion is not enough, however, and Philip had to explain that this prophesy had come to pass. Christ was not only dead and buried, but also resurrected. Philip used Isaiah to tell the good news of Jesus; we read about Jesus in the New Testament.
The Lord’s supper can be seen in the Passover story. Jesus said he must be “lifted up” as the brass serpent was lifted up by Moses. The whole temple system, (the building, the veil, the priest, the sacrifice, the Holy of Holies) is all about Jesus. But all of these are symbols; they’re all pictures of what was to come. To be the gospel, they require explanation.
Abraham was willing to sacrifice Isaac, but then offered the ram instead. Without explanation from a New Testament point of view, this is just a terrifying account of a guy that almost chopped up his son on an alter. The Holy Spirit brought Philip to the Ethiopian Eunuch that day in order to open his eyes to the saving work of Jesus Christ. I could use Old Testament passages to explain how to receive Christ, but I do not believe you could read only O.T. enough times to do it with no knowledge whatsoever of the N.T. Gospels.
So the answer to the original question becomes “Yes, but…”