In John 3, for example, He compared himself to the brazen serpent. Just as Moses lifted up the snake in the desert, so the son of man must be lifted up, that everyone who believes in him may have eternal life. The brazen serpent was a type of Christ. In John 6 Jesus said that the manna was a symbol that pointed to him as well. He who comes to me will never go hungry, and He who believes in me will never be thirsty.
Types then are like object lessons.
Each one reveals a different aspect of the personality and work of the Son of God. The Apostle Paul spoke about the rock that Moses struck in desert from which water flowed. And we understand that just as the rock was smitten by Moses, so Christ was pierced on the cross and the symbol of the water flowing speaks of the Holy Spirit that our Lord made available to us through his death and resurrection. For his life from beginning to end foreshadows the life of our Lord in greater detail and with more frequency than any other Old Testament character. But to the man on whose heart the cross is carved in loving memory, there is a far deeper interest.