20 And it was not without an oath! Others became priests without any oath,
21 but he became a priest with an oath when God said to him: “The Lord has sworn and will not change his mind: ‘You are a priest forever.’ ”
22 Because of this oath, Jesus has become the guarantee of a better covenant.
(Heb 7:20-22)

Sermon Main Points
1) God has sworn an oath that Jesus is high priest
2) God has sworn an oath that Jesus is high priest forever
3) God will not change his mind that Jesus is high priest
4) God has a guarantee that Jesus is high priest