Hebrews 5:3

For every high priest, being taken from among men, is appointed for men in things pertaining to God, that he may offer both gifts and sacrifices for sins.

The high priest can deal gently with those who are ignorant and going astray, because he himself is also surrounded with weakness.

Nobody takes this honor on himself, but he is called by God, just like Aaron was.

So also Christ didn’t glorify himself to be made a high priest, but it was he who said to him,

“You are my Son.

Today I have become your father.”

As he says also in another place,

“You are a priest forever,

after the order of Melchizedek.”