There is a classic and rather an obvious problem with combining two Christian ideas: (i) that God is infinitely loving, knowledgeable, and powerful and (ii) Hell is a real possibility for us. Now we have to be careful how we state the second point here. As I understand the Catholic view here, ending up in hell is a real possibility for each of us, but we do not know for sure whether anyone has ever actually ended up there (see the 2013 film Hellbound for more on different conceptions of Hell.) Catholics cannot say who (if anyone) has ended up there nor can we say today who will. But we could end up there. It is a real possibility.
How can we hold both of these views at the same time? Wouldn't an infinitely loving and powerful God make hell impossible?
In his wonderful new book, The One Thing That is Three: How the Trinity Explains Everything (2012), Michael Gaitley suggests a response (which has, of course, been proposed elsewhere.) The idea is: Just as all came from God, so all will eventually return to God. The only question is what kind of person we will be when we arrive at the source of everything (namely, infinite Love.) Three options seem possible. First, one could fully accept this infinite Love and enjoy it (heaven). Second, one could partly accept it and grow to accept it over time (purgatory). Third, one could hate it and reject it (hell).
Of this third option, Gaitley writes, the soul that has been confirmed in selfishness in this life just may come to see the self-giving love of the Trinity as a kind of torture. This comment suggests the idea that heaven and hell may be the same place the only difference between the two is the kind of person one is. One is cut off from God not by anything external, but only by things internal to one's own self. Hell is eternal for those who have characters such that they can never change.
I find this view rather appealing as a statement of the orthodox view. It seems fairly just insofar as only those who could never grow to accept the infinite Love are left in never-ending torment (the torment of being loved and never being able to accept it.) Perhaps they experience the Divine Love as an eternal fire?
An alternative view to the classic orthodox view is known as Annihilationism whereby damned souls are simply destroyed. As Jerry Walls points out in Hell: The Logic of Damnation (1992), there are passages in the Scriptures to support this view. But The orthodox asks could Divine Love destroy these souls? Maybe not, if doing so would be unloving (and so contrary to the Divine nature.) It may be God's infinite Love itself which (ironically) opens up the possibility of hell (namely to those who are such that this love makes the miserable and could never accept it.) c Because the damned souls have value objectively and are worth loving, destroying them may be an unloving act. So God won't do it. But this then leaves open the possibility of living with an eternal embrace that makes one miserable.