John Calvin Commentary Hebrews 4:14

"Having then a great high priest, who hath passed through the heavens, Jesus the Son of God, let us hold fast our confession." — Hebrews 4:14 (ASV)

Seeing then that we have, or, Having then, etc. He has been until now speaking of Christ’s apostleship. But now he passes on to His second office. For we have said that the Son of God sustained a twofold character when he was sent to us, even that of a teacher and of a priest.

The Apostle, therefore, after having exhorted the Jews obediently to embrace the doctrine of Christ, now shows what benefit His priesthood has brought to us; and this is the second of the two points which he handles. And fitly does he connect the priesthood with the apostleship, since he reminds us that the design of both is to enable us to come to God. He employs an inference, then; for he had before referred to this great truth, that Christ is our high priest. But as the character of the priesthood cannot be known except through teaching, it was necessary to prepare the way, so as to make people willing to hear Christ. It now remains that those who acknowledge Christ as their teacher should become teachable disciples, and also learn from His mouth, and in His school, what is the benefit of His priesthood, and what is its use and end.

In the first place he says, Having a great high priest, Jesus Christ, let us hold fast our profession, or confession. Confession is here, as before, to be understood as a metonymy for faith. And as the priesthood serves to confirm the doctrine, the Apostle therefore concludes that there is no reason to doubt or to waver concerning the faith of the Gospel, because the Son of God has approved and sanctioned it. For whoever regards the doctrine as not confirmed dishonors the Son of God and deprives Him of His honor as a priest. Indeed, such and so great a pledge ought to make us confident, so as to rely unhesitantly on the Gospel.