Hebrews 7:11

Now if perfection were by the Levitical priesthood, (for under it the people received the law) what farther need was there that another priest should arise after the order of Melchisedec, and not after the order of Aaron?

Hebrews 8:7

For if the first covenant had been unexceptionable, there had been no room for a second:

Galatians 2:21

I do not frustate the grace of God: for if righteousness be by the law, then Christ died in vain.

Hebrews 5:6

As He saith also in another place, "Thou art a priest for ever after the order of Melchisedec."

Hebrews 7:17-19

For He testifieth, Thou art a priest for ever after the order of Melchisedec.

Galatians 4:3

So we when we were children, were in servitude under the elements of the world:

Galatians 4:9

But now that ye know God, or rather are known by God, how is it that ye turn again to the poor weak elements, to which ye desire again to be in bondage as before?

Colossians 2:10-17

And ye are complete in Him, who is the head of all principality and power.

Hebrews 5:10

having been declared by God an high-priest after the order of Melchisedec.

Hebrews 6:20

Whither Jesus our fore-runner is entered for us, being made an high-priest for ever, after the order of Melchisedec.

Hebrews 7:15

And it is yet more abundantly evident, that after the similitude of Melchisedec there ariseth another priest,

Hebrews 7:21

(for they indeed are become priests without the solemnity of an oath; but He with an oath, by Him who said unto Him, "The Lord hath sworn, and will not repent, Thou art a priest for ever after the order of Melchisedec:")

Hebrews 8:10-13

But this is the covenant that I will make with the house of Israel after those days, saith the Lord, I will put my laws into their mind, and I will inscribe them on their hearts; and I will be to them a God, and they shall be to me a people.

Hebrews 10:1-4

For the law having but a faint shadow of good things to come, and not the full image of the things, can never, even by the great annual sacrifices which they offer statedly, make the comers thereunto perfect.

Treasury of Scripture Knowledge

Summary

If therefore perfection were by the Levitical priesthood, (for under it the people received the law,) what further need was there that another priest should rise after the order of Melchisedec, and not be called after the order of Aaron?

Bible References

Perfection

Hebrews 7:18
For there is indeed a disannulling of the preceding command, on account of it's weakness and unprofitableness;
Hebrews 8:7
For if the first covenant had been unexceptionable, there had been no room for a second:
Hebrews 10:1
For the law having but a faint shadow of good things to come, and not the full image of the things, can never, even by the great annual sacrifices which they offer statedly, make the comers thereunto perfect.
Galatians 2:21
I do not frustate the grace of God: for if righteousness be by the law, then Christ died in vain.
Galatians 4:3
So we when we were children, were in servitude under the elements of the world:
Colossians 2:10
And ye are complete in Him, who is the head of all principality and power.

What

Hebrews 7:26
For such an high-priest was meet for us, who was holy, harmless, undefiled, separate from sinners, and higher than the heavens;

Another

Hebrews 7:15
And it is yet more abundantly evident, that after the similitude of Melchisedec there ariseth another priest,
Hebrews 5:6
As He saith also in another place, "Thou art a priest for ever after the order of Melchisedec."
Hebrews 6:20
Whither Jesus our fore-runner is entered for us, being made an high-priest for ever, after the order of Melchisedec.