Why? To what purpose?
Who is God displaying His mercy too?
"And you were dead in your trespasses and sins, in which you formerly walked according to the course of this world, according to the prince of the power of the air, of the spirit that is now working in the sons of disobedience. Among them we too all formerly lived in the lusts of our flesh, indulging the desires of the flesh and of the mind, and were by nature children of wrath, even as the rest. But God, being rich in mercy, because of His great love with which He loved us, even when we were dead in our transgressions, made us alive together with Christ (by grace you have been saved), and raised us up with Him, and seated us with Him in the heavenly
places in Christ Jesus,
so that in the ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus. For by grace you have been saved through faith; and that not of yourselves,
it is the gift of God; not as a result of works, so that no one may boast. For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand so that we would walk in them" Ephesians 2:1-10
Regarding to whom this mercy is displayed to in the ages to come - there are, I suppose, at least 4 situations that come to mind.
Future creations of the kind He did here on earth. In which case, just humanly surmising, He may substitute the things learned in this age (mercy, grace, justice against rebellion, wrath etc.) for the tree of the knowledge of good and evil through which we learned these things.
Different kinds of creation from this earthly kind (angelic, totally different from angels and me etc.).
The inhabitants of earth in Christ's Millennial reign.
The nations which are referred to in the book of Revelation. Revelation chapter 21: "
9 Then one of the seven angels who had the seven bowls full of the seven last plagues came and spoke with me, saying, “Come here, I will show you the bride, the wife of the Lamb.
(US) 10 "And he carried me away in the Spirit to a great and high mountain, and showed me the holy city, Jerusalem, coming down out of heaven from God, 11 having the glory of God..........24
The nations will walk by its light, and the kings of the earth will bring their glory into it. 25 In the daytime (for there will be no night there) its gates will never be closed; 26 and they will bring the glory and the honor of the nations into it; 27 and nothing unclean, and no one who practices abomination and lying, shall ever come into it, but only those whose names are written in the Lamb’s book of life."
But then - it doesn't depend on me or anyone else either finding who may have God's mercy displayed to in scripture or ruminating about what may be in the ages to come that has not been revealed to us.
What is important is that we realize that both His mercy and wrath will be on display in the ages to come and that (it doesn't seem) this whole "knowledge of good and evil" encompassed age will not have to be repeated -
EVER (as I read things).