Wherefore in all things it behoved him to be made like unto his brethren, that he might be a merciful and faithful high priest in things pertaining to God, to make reconciliation for the sins of the people. Wherefore in all things - Because he thus laid hold on man in order to redeem him, it was necessary that he should in all things become like to man, that he might suffer in his stead, and make an atonement in his nature.
That he might be a merciful and faithful high priest - Ἱνα ελεημων γενηται· That he might be merciful - that he might be affected with a feeling of our infirmities, that, partaking of our nature with all its innocent infirmities and afflictions, he might know how to compassionate poor, afflicted, suffering man. And that he might be a faithful high priest in those things which relate to God, whose justice requires the punishment of the transgressors, or a suitable expiation to be made for the sins of the people. The proper meaning of ἱλασκεσθαι τας ἁμαρτιας is to make propitiation or atonement for sins by sacrifice. See the note on Luke 18:13, where it [this word] is particularly explained. Christ is the great High Priest of mankind;
1. He exercises himself in the things pertaining to God, taking heed that God's honor be properly secured, his worship properly regulated, his laws properly enforced, and both his justice and mercy magnified. Again,
2. He exercises himself in things pertaining to Men, that he may make an atonement for them, apply this atonement to them, and liberate them thereby from the curse of a broken law, from the guilt and power of sin, from its inbeing and nature, and from all the evils to which they were exposed through it, and lastly that he might open their way into the holiest by his own blood; and he has mercifully and faithfully accomplished all that he has undertaken.