Hebrews 5:1-4

For every high priest chosen from among men is appointed [to act] on behalf of men in things relating to God, so that he may offer both gifts and sacrifices for sins. He is able to deal gently with the spiritually ignorant and misguided, since he is also subject to human weakness; and because of this [human weakness] he is required to offer sacrifices for sins, for himself as well as for the people. And besides, one does not appropriate for himself the honor [of being high priest], but he who is called by God, just as Aaron was.