'Mediator' in the Bible

Why then the law? It was added for the sake of transgressions, until the seed came to whom the promise was made, ordained through angels in the hand of a mediator.

But a mediator is not of one, but God is one.

For God is one, and the mediator of God and men one, the man Christ Jesus,

But now he has got a more excellent ministry, by so much as he is mediator of a better covenant, which is established on the footing of better promises.

And for this reason he is mediator of a new covenant, so that, death having taken place for redemption of the transgressions under the first covenant, the called might receive the promise of the eternal inheritance.

and to Jesus, mediator of a new covenant; and to the blood of sprinkling, speaking better than Abel.