The Bible
Hebrews 5
For a man to hold the priesthood, he must be called of God as was Aaron—Christ was a priest forever after the order of Melchizedek—Jesus Christ is the Author of eternal salvation.
3And by reason hereof he ought, as for the people, so also for himself, to offer for sins.
4And no man taketh this honour unto himself, but he that is called of God, as was Aaron.
6As he saith also in another place, Thou art a priest for ever after the order of Melchisedec.
8Though he were a Son, yet learned he obedience by the things which he suffered;
9And being made perfect, he became the author of eternal salvation unto all them that obey him;
10Called of God an high priest after the order of Melchisedec.
11Of whom we have many things to say, and hard to be uttered, seeing ye are dull of hearing.
13For every one that useth milk is unskilful in the word of righteousness: for he is a babe.