Strong’s Dictionary says “paradise” derives from the Hebrew pardec, meaning an orchard or forest. It’s a reference back to Eden. This is strongly suggested by–
(Rev. 2:7b) To him who overcomes, I will give the right to eat from the tree of life, which is in the paradise of God.
The tree of life was, of course, originally in the Garden of Eden.
But we have to also consider Revelation 22, which immediately follows the prophecies of the New Heaven and New Earth in Revelation 21–
(Rev 22:1-2) Then the angel showed me the river of the water of life, as clear as crystal, flowing from the throne of God and of the Lamb 2 down the middle of the great street of the city. On each side of the river stood the tree of life, bearing twelve crops of fruit, yielding its fruit every month. And the leaves of the tree are for the healing of the nations.
(See also verses 14 and 19).
If the tree of life is in Paradise and if it’s in the New Jerusalem, then Paradise is the New Jerusalem.
I suppose you could argue that the tree will be transplanted at the End from Paradise to the New Jerusalem on the New Earth. But the New Jerusalem is already in heaven, being prepared for us (John 14:1-4; Rev. 21:2). It makes far more sense to imagine the tree of life in the New Jerusalem in preparation for its descent to the New Earth, rather than being transplanted a second time.
And if the New Jerusalem is Paradise, then the New Jerusalem is Eden reborn, which fits the prophecies perfectly. After all, we are told in Revelation 22:3–
(Rev. 22:3) No longer will there be any curse. The throne of God and of the Lamb will be in the city, and his servants will serve him.
Clearly, John is telling us that the End, the coming of the New Heaven and New Earth, will end the curse of Genesis 3 and return us to Eden.
Now, the leaves Jesus words to the thief on the cross as a bit of a mystery, as he promised him Paradise “today.” But we’ll have to wait to get to that one.