Hey man. I would highly advise you that you do not argue against the Apostle that wrote Heb 8:13. You will lose, no questions asked. Besides, there is nothing in the Bible that contradicts Heb 8:13.
Interesting thing about Hebrews 8:13 is the addition of a word by the KJV translators that is not in the best Greek texts from which Hebrews was translated. It's the word "covenant."
It was added by the translators in what is commonly called "leading the witness."
10 For 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 write them in their hearts: and I will be to them a God, and they shall be to me a people:
11 And they shall not teach every man his neighbour, and every man his brother, saying, Know the Lord: for all shall know me, from the least to the greatest.
12 For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more.
13 In that he saith, A new
covenant, he hath made the first old. Now that which decayeth and waxeth old is ready to vanish away.
Heb 8:9–13.
By adding that word just might not be what the author of Hebrews had in mind. And because that word was added that may not even be what the author of Hebrews was writing about many, many Gentiles read the verse but "covenant" is not being referred to in that verse. I thinks you should consider this and not be so dogmatic when "covenant" was added by the translators and just might be leading you astray. And if the context might seem as though "covenant" added does belong I have to say that when that "ready to vanish away" might happen? Most likely it might vanish away when everything is said and done and human history is over and God's elect are with Him in eternity? The Old "covenant" might be old but while we are still in our present time in history it has not yet vanished because God is STILL using it in various ways. Here's a couple of those ways:
16 All scripture (referring to the Old covenant) is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:
17 That the man of God may be perfect, throughly furnished unto all good works.
2 Tim. 3:16–17.
It is STILL profitable for doctrine, reproof, correction, and instruction in righteousness today and most likely tomorrow, too, and the next day after that...and...
and...
23 But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed. 24 Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith.
Gal. 3:23–24.
The Old "covenant" will be used of God so that the children of Israel can be brought to Christ. The implication is that if the Old "covenant" has "vanished away [today] that the children of Israel cannot be brought to Christ, and according to Revelation Israel still needs to "come to Christ (their Messiah and King."
Guess what? The Law has been fulfilled in Christ. You are 2000 years behind the times. Try to keep up.
Yes, and the New Covenant in Christ's blood instituted at the 'last supper' in only the Mosaic Covenant fulfilled and by the Law being nailed to His cross died with Him and was also raised in newness of life so that since the Law is spiritual it is the Old "covenant" law that is put in our inward parts so that we may obey the Old "covenant" Law from within instead of when it was leading and guiding the children of Israel from without written on stone.
(2 Cor 3:6) who also made us sufficient as ministers of the new covenant, not of the letter but of the Spirit; for the letter kills, but the Spirit gives life.
The Law killed because men were carnal and of the flesh. But when Jews began to be born again then natural Olive tree Israel became spiritual Olive tree Israel. And there is more to say on this subject, but from what I read in Scripture the Old "covenant" still exists to fulfill the purposes of God towards His people Israel. So, it hasn't vanished away yet.
Your letter of the Law of the old covenant kills; whereas, the Spirit of the New Covenant gives life. Don't ever tell me I never warned you.
The Law killed because men were flesh. But when men became spiritual the Law cannot 'touch' them anymore and is the Old "covenant" Law that is put in the believer's inward parts and that Old "covenant" still fulfills the purposes of God until human history ends and God's elect are finally with Him
We still need to not have other gods before us and not steal or take the LORD'S Name in vain, etc., etc.