Yes, there can be and actually are more than just one covenant, but according to Torah and Tanakh, the Abrahamic Covenant and the Mosaic Law are "forever" and "perpetual", and that shouldn't be ignored.
So many of the books in the Tanakh, including Isaiah, put observance and non-observance of the Law as being paramount, so why would God punish those who do not honestly try and observe the entire Law (all 613) and then supposedly turn around and have it that the Law really wasn't important after all.
However, just a reminder that non-Jews are not bound by either, so it certainly is at the least hypothetically possible that God could have a covenant with them.
Hi Metis,
I am going to mention that which you hoped I would somehow avoid.
The fact is the whole of the law was to be obeyed and we know that no man but Jesus Christ, ever did that.
We also know the Father of the Faith, Abraham and his descendants through Isaac were not subject to the laws at the time Abraham found favour with God.
We know Abraham knew about God because God was there at the beginning with the first man Adam.
We know Abraham descended from Adam and that Abraham believed what God told him about his Son and this God himself accounted as righteousness toward Abraham.
Abraham put right with God through faith in Gods words.
When Moses lead the Israelites out of Egypt he did this because God remembered his promise to Abraham.
He gave them a covenant based on the laws. We also had the Prophets teachings included.
We had the sacrifices and the purpose God revealed them to the Israelites.
The Israelites the Jews knew that anyone who obeyed God and did what was right in Gods sight were acceptable to him.
For Abraham it was faith in Gods words and promises to him about his Son.
He believed God even to the point he knew death would not prevent God keeping his promise.
So we come to last covenant and main covenant of Jeremiah 31:31-34.
A covenant not like the old with Moses when he brought them out of Egypt.
But a covenant where God is known to man and his laws are written on their hearts and they obey God.
The Father of faith Abraham, the Prophets and all who truly knew God were anointed with Gods Holy Spirit.
Men believe what God has said about his Son Jesus Christ and God accounts this as righteousness taking away the sin
and allowing them to know him and live by faith according to the NT and the OT.
Outside the Abrahamic covenant (which were promises God made which required nothing but for Abraham to believe)
We see there are no covenants only those through the line of Isaac and to present day though the Messiah.
According to Gods own laws, Prophet's and teachings, there is only one possible line of covenants and it is covered completely within his word both OT and NT.
The NT being the fulfilling of the OT teachings of the Law and Prophets.
God made a covenant with Isaac and Jacob. He only blessed Ishmael he was never chosen and neither was any other religion nor any other covenants/ religious books valid.
I personally, see the OT as the ONLY book/s ever referred to by God, Jesus, The Prophets and disciples as Holy Scripture.
As the new way and covenant came in by the Messiah to live in Spirit and Truth. Then the word source living in mankind means Gods work is complete. The power of Gods Spirit
to lead and teach every man as he did the Prophet's and chosen of God throughout the OT.
The Words of God, (I believe the bible shows) as with Abraham and Moses should lead people to a living relationship with the One true and Almighty powerful God.