Concerning the dispensationalist/covenant theology argument, which is assuredly foundational to the amillennial issue, I would suggest that the real issue with dispensationalism involves how they read NT references to the OT.
The apostles and Christ were definitely not dispensational in how they used OT Scripture, as they take Scripture applying to Israel and apply it to Jesus or believers, who are Jesus' body.
For example, you can read Matthew and see that Matthew takes Scriptures applying to Israel and applies them to Jesus.
Matthew 2:14-15 4 And he rose and took the child and his mother by night and departed to Egypt 15 and remained there until the death of Herod. This was to fulfill what the Lord had spoken by the prophet, “Out of Egypt I called my son.”
Hosea 11:1 1 When Israel was a child, I loved him,
and out of Egypt I called my son.
Why?
Jesus is true Israel.
And, Matthew does this over and over again in his gospel. That is because he wanted to show them that Jesus was the true Israel, as well as being the true Adam. He defeated evil, whereas the first Adam and first Israel did not. That is why the desert temptation scene is presented in Matthew 4. It was an echo of Adam's testing in the Garden of Eden, and Israel's testing in the wilderness.
And, Peter does the same thing for the Church when he takes Scriptures applying to Israel in Exodus 19 and alludes to them in his epistle.
Exodus 19:5-6 5 Now therefore, if you will indeed obey my voice and keep my covenant, you shall be my treasured possession among all peoples, for all the earth is mine; 6 and you shall be to me a kingdom of priests and a holy nation.’ These are the words that you shall speak to the people of Israel.”
1 Peter 2:9-10 9 But you are a chosen race, a royal priesthood, a holy nation, a people for his own possession, that you may proclaim the excellencies of him who called you out of darkness into his marvelous light. 10 Once you were not a people, but now you are God's people; once you had not received mercy, but now you have received mercy.
Why?
The Church, as Jesus' body, is True Israel.
It's really not hard to figure out that the Apostles believed in "covenant theology" because they take Scriptures applying to Israel and apply them to Jesus or the Church.
GK Beale and DA Carson wrote a long commentary where they examine every incidence where the NT quotes or alludes to the OT. It is on my reading list.
https://smile.amazon.com/Commentary...ed+in+the+new+testament&qid=1583315983&sr=8-2
Somehow I don't think many dispensationalists will be reading this. I plan on buying a copy though