When Adam and Eve rebelled against God in the garden, we became like a branch that sawed itself off from the tree.  In our attempt to find satisfaction apart from God, we separated ourselves from our very life source.  But God was not willing to leave us in our brokenness.  Jesus comes as our High Priest, the only one who could be the go-between, the only one who could truly restore us to the Father.  The Old Testament ritual of the high priest was a shadow of what Jesus would complete for us.