I don’t know if I can really engage in a lengthy discussion, but I have a few quick comments.
Insofar as Catholic theology views concupiscence, or inclinations towards sin, I’d like to frame how this is removed when we go to Heaven. It’s not some additional part that is taken away. It’s more of a wound that is healed, or like blindness being restored. Imagine a human being as a painted vase with many cracks running through it. A person being perfected when they go to Heaven is like the vase being perfected and the cracks removed/fixed as if they were never there. But I mean, you don’t remove a crack anymore than you remove a hole, except insofar as you’re referring to how you fill in an empty space.
Insofar as when the body is restored at the resurrection, the body is still changeable, but it is fashioned (and this is just a theological response based on Christian revelation and not something one would deduce if one was just working from the point of observation of nature alone – the resurrection in general is a revelation not something known by natural philosophy) in a way that is fitting to the perfected person, and such that the person’s intellect properly rules the bodily appetites. The person who has the beatific vision has also obtained their highest good, the thing all other possible goods try to approximate, and the person truly finds a rest in their appetites in having obtained it.
The next part is not a response to why the problem of evil is not contradictory with God’s nature. I’ve attempted to lay out a response to that problem in another post on the board, but that’s not what this post is. However, taking for granted that the problem of evil is not in conflict with God’s nature, then why does God allow it? One response may be because it brings about some greater good, but in what way? Such… diversity… allows for many different types of being to be instantiated, which makes the universe more of an image of God than if fewer, finite types were present and other types were not expressed. Similarly, there are certain virtues that could not be developed and expressed in nature without such discrepancies, from what we’d call self-less charity or courage. These are types of goods that would not be present otherwise, and we are really allowed to participate in and develop these things in ourselves through our own agency (and intellect and volition are also types of goodness in God). The diversity and greater variety of goods is therefore better (in terms of manifesting and sharing God’s own being) than a more limited reality.
