I think perhaps the translation you are using is wrong. In my Bible it says this:
Ephesians 2:15
15 Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace;
So then this would still be in harmony since Jesus is not abolishing the law, but rather fulfilling the law by abolishing the enmity in the law in his flesh (by being crucified, and thus being a perfect sacrifice to make atonement for the sins of the people.)
“For it is evident that our Lord sprang out of Juda; of which tribe Moses spake nothing concerning
priesthood. who is made,
not after the law of a carnal commandment, but after the power of an endless life. For he testifieth, Thou art a priest for ever After the order of Melchisedec.
For
there is verily a disannulling of the commandment going before for the weakness and unprofitableness thereof. For the law made nothing perfect,
but
the bringing in of a better hope did; by the which we draw nigh unto God.
By so much was Jesus made a surety of
a better testament. but this man, because he continueth ever, hath an unchangeable priesthood. Wherefore he is able also to save them to the uttermost that come unto God by him, seeing he ever liveth to make intercession for them.”
Hebrews 7:14, 16-19, 22, 24-25 KJV
there is a disannuling of the law to bring forth the gospel
the new and better covenant
“The
law and the prophets were until John:
since that time the kingdom of God is preached, and every man presseth into it.”
Luke 16:16
the gospel the new and better testament is what draws us near to God so we can live .
“Verily, verily, I say unto you,
He that heareth my word, and believeth on him that sent me,
hath everlasting life, and shall not come into condemnation; but is passed from death unto life.”
John 5:24 KJV
the law is what commanded man to remain far away and refuse to hear so we don’t die
“Now therefore
why should we die? for this great fire will consume us:
if we hear the voice of the LORD our God any more, then we shall die.”
Deuteronomy 5:25 KJV
the law of Moses ran up until Jesus died and rose at that point everything Jesus said became Gods everlasting word. Because the testament is new and seperate the priesthood needed to change when it did the word ofnthe priest became Christs word and was no longer the levites of Moses law
the levites gave the law and ruled over the people by it
“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?”
Hebrews 7:11
this seperate priesthood means there are seperate covenant words
“For
the priesthood being changed, there is made of necessity a change also of the law.”
Hebrews 7:12 KJV
The priest abides over the word he gave an oath to and for Jesus and his word is the new testsment moses words were about Jesus and he fulfilled them