Contradiction with Hebrews 7:12
States that with a change in priesthood comes a change in the law, implying the Levitical priesthood is temporary, unlike the eternal priesthood of Melchisedec.
Hebrews 7:12: For the priesthood being changed, there is made of necessity a change also of the law.
Contradiction with Numbers 25:13
God's covenant of a perpetual priesthood is with Phinehas and his descendants, suggesting the Aaronic priesthood's permanence.
Numbers 25:13: And he shall have it, and his seed after him, [even] the covenant of an everlasting priesthood; because he was zealous for his God, and made an atonement for the children of Israel.
Contradiction with Exodus 40:15
Speaks of the priesthood as an "everlasting priesthood" for Aaron and his sons, which suggests a contradiction to the Melchisedec priesthood being forever.
Exodus 40:15: And thou shalt anoint them, as thou didst anoint their father, that they may minister unto me in the priest's office: for their anointing shall surely be an everlasting priesthood throughout their generations.
Contradiction with Hebrews 8:4
Indicates that if Christ were on earth, he would not be a priest, contrasting with the eternal priest role mentioned in Hebrews 7:17.
Hebrews 8:4: For if he were on earth, he should not be a priest, seeing that there are priests that offer gifts according to the law: [there...: or, they are priests]
Contradiction with Psalms 110:4
Is referenced in Hebrews 7:17, yet also emphasizes the Lord's oath, contradictory to needing a change or succession of priesthoods as seen through historical practices.
Psalms 110:4: The LORD hath sworn, and will not repent, Thou [art] a priest for ever after the order of Melchizedek.