Jesus is no Aaronic priest. His priesthood is of a different order, that of Melchizedek. Several important things separate this priesthood from the Aaronic, but the big one is that Jesus, the final High Priest, is able to save eternally and completely those who come to God through him.
God warns us to not make the same mistakes Israel made of looking merely to earthly rest. The true “rest” that was promised to Israel was not Canaan–it was something greater and not fully realized until the coming of Jesus Christ. If we are to enter, however, we must strive diligently to do so and not be distracted by fatal unbelief.
In an encounter with Nicodemus, Jesus seeks to expose what the most important issue is: the need for rebirth. Like all of us, Nicodemus was preoccupied with the things on the surface, but real change and real relationship with God starts with a new heart.
When Israel murmured against God about going back to Egypt God sent the symbol of Egypt (“fiery” serpent) to curse and remind them that there is no protection or salvation in Egypt. But all of this was just pointing to something greater, namely, The Curse that was lifted up on a pole at Golgotha named Jesus.