Messiah as Mediator
“Nathan proclaimed that each Jew should give the messiah spiritual force in the form of faith in him, and the messiah will then focus the powers of the whole people to achieve the final victory over the forces of evil. Thus, Nathan introduced into Judaism the concept of a mediated religious relationship with God, giving the messiah (for the first time in a millennium and a half) the role of being the intermediary between the worshipper and the supreme Godhead, and allotting to him a position of an incarnated divine power.”
Conversely, “Luria and his disciples described a direct relationship between man and God, and viewed the tikkun as the involvement of every individual in the process of redemption…”
–Joseph Dan, Kabbalah: A Very Short Introduction, pg. 87-8.