What is the Everlasting Covenant? - Conclusion

And so there are:
Circumcision, Genesis 17:7
The Sabbath, Exodus 31:16
and Jesus, Hebrews 13:20
All three are called everlasting covenants.  Which is it?...
(Update--There is one more possibility in my next post "One More Thing."  Don't miss it!)
The covenants of circumcision and the Sabbath are altered in the New Testament.  They were not required for Gentile believers, and though the Jewish believers continued them, they recognized that the acts of circumcision and keeping the Sabbath were not what brought them salvation, but their faith--belief in the Lord Jesus.  So in a way, we could say they were swallowed up into the covenent concerning Jesus.  That points us to the covenant described in Hebrews 13:20.

Now may the God of peace who brought up our Lord Jesus from the dead, that great Shepherd of the sheep, through the blood of the everlasting covenant

While looking up "everlasting covenant" I saw that there are six verses that say God will make an everlasting covenant with His people.  They don't say exactly what it will be, but that it will happen.  Here they are:
Isaiah 55:3 and 61:8
Jeremiah 32:40 and 50:5
Ezekiel 16:60 and 37:26

Those verses point to a time which was in the future for Isaiah, Jeremiah, and Ezekiel.  Jesus and His everlasting covenant was in the future for them, and so it still fits.  And Isaiah 55:3 can provide confirmation:
Incline your ear, and come to Me.
      Hear, and your soul shall live;
      And I will make an everlasting covenant with you—
      The sure mercies of David.
"David" was a prophetical name used for Christ.  You can see it in Jeremiah 30:9, Ezekiel 34:23-24 and 37:24-25, and Hosea 3:5.

But the question that remains is, what is our part in keeping (or accepting) this everlasting covenant through Jesus. Is it keeping the Passover with all the particular regulations as the WMSCOG says, or is it something else? That's a good question for another day...

By the way, when my sister asked me this question, this is exactly what I did.  I started looking in my Bible for every instance of "everlasting covenant" and listing the possibilities.  That's when things got difficult with the conversation, and we didn't get any farther.  I don't know if it was something about the way I was studying the Bible, or if it was the result of pent up frustrations after some heated discussions.  But it's too bad, because I think we would have at least agreed on the right section of the Bible to settle on.

Click here for a little more on the Everlasting Covenant.