For Edwards the Mediator is indeed divine and the pre-existent eternally generated Son of God.” Christ was sent to be the Mediator of the Covenant as the object of God’s love. Only Christ was sent as the Mediator, not God and not the Holy Spirit because of who Christ was and is and always will be.
I have heard it said that Christ is the “transformer” between us, as unholy sinners, and an infinitely Holy God. With Him we would be unable to “plug into” the power of God because we would explode. I believe that this is why there is Jesus Christ the Mediator and I feel that this is the way Edwards felt.