'Mediator' in the Bible

Why, then, the law? on account of the transgressions it was added, till the seed might come to which the promise hath been made, having been set in order through messengers in the hand of a mediator --

and the mediator is not of one, and God is one --

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

and now he hath obtained a more excellent service, how much also of a better covenant is he mediator, which on better promises hath been sanctioned,

And because of this, of a new covenant he is mediator, that, death having come, for redemption of the transgressions under the first covenant, those called may receive the promise of the age-during inheritance,

and to a mediator of a new covenant -- Jesus, and to blood of sprinkling, speaking better things than that of Abel!