John Dussinger brings up the above final question of the novel, to which I agree the answer, from all that has gone before, must be yes.
I would say the novel Clarissa testifies to strong belief in God's will working itself out in the world. We are to take all Clarissa's preparation as necessary; we are to believe in her "assurances" (a word used in the literature of conversion experience) before she dies; all the deaths of the wicked people show they are now and will continue to be severely punished: Lovelace's dream, Mrs Sinclair's terror, the death of Belton all bear witness to the belief of Richardson's characters at least (and by extension their creator and his expectations about his audience) that there are horrifying devils waiting in some dark pit eager to torture them for a very long time. Lovelace himself dies in a duel; the Bible prohibits people from taking vengeance into their own hands, now while, therefore, Morden is a murderer, in a duel it's murder or be murdered; so if you set forth to a duel, you set forth to kill, so Lovelace died in an attempted murder of Morden. Not exactly the road to Heaven I'd say.
Now John also talks about the 1960's which are said to have been this very liberal era, and seems to suggest that our discomfort with Richardson's views come from our liberal environment. I would say no. Well, maybe in the cant repeated in the 1960's and until recently in the newspapers (now it's a different and I submit worse cant), and it's true that in 1972 about 39% of the population voted for McGovern, and from 1965 until Saigon fell many many people did not want their sons to die in Vietnam. But it was in the 1960's in my senior year in high school that I used to eat lunch with 3 young women seniors, 7th Day Adventists (why they ate lunch with me is another story--but they did), and they believed Christ was coming any minute now, and they controlled their minute-to-minute conduct accordingly. No movies, no dancing, no drinking liquor. It was in the 1960's for a brief time I attended a Protestant church where a minister used to go on about hell and mean it, and his listeners sat there with no surprize whatsoever. Three years ago in a classroom at GMU a student said in fervent tones he believed absolutely in Adam and Eve and every word of the Bible was true; when I have shown a brilliant performannce of the Yorkshire Mystery plays to classes at GMU, when we get to the Passion students get upset for real; they are really disturbed by the comic portrayal of hell. The United States is no different from other countries: they are filled with people who can profess a belief in horrifying punishments for other people, and in their weaker moments, maybe themselves, though they will say they are working at it, and probably do not think they will be damned. Those who really do may end like poor Cowper, or take to other desperate neurotic behaviors.
So I would say that looking across the broad spectrum of a couple of billion people on this earth, the vocal liberals in a few books are rare on the ground (Hume is still a rare rare man), but still because people today may still believe in this eschatology, by no means does this make the idea that we are to rejoice that someone who has done evil is to be tortured for all eternity a truly moral or decent or humane (or whatever word you want to use) response. It is as vile as the act of capital punishment.
Nor do I think that the argument we must forgive this because after all many people still think this way now and certainly thought this way in 18th century England will stand up-- if we want to make Clarissa into one of the abidingly great books of world literature. First of all there's real evidence from the Renaissance (Lefebre's books) and even earlier (Ginsburg's and other books) than that, that people for centuries before and in the 18th century and disbelieved it from a sense the whole eschatalogy is improbable (not in accordance with their experience) or abhorrent. As we all know many historians & literary and other scholars have suggested that in the 18th century the belief in a real hell was in a real decline (e.g. D.P. Walker's The Decline of Hell: 17th Century Discussions of Eternal Torment); the latitudinarian divines like Tillotson and Southwell (whom I have read) emphasize the goodness of the moral life, and seem, so to speak, to avoid the unpleasant topic of hell; in books like Tom Jones the idea of a benevolent deity can be seen clearly to be making headway, But there were the backwaters such as Godwin came from, and the Calvinistic view emphasizes God as all-powerful and man as vicious.
Now of course it's hard to know what people think at any given time because the press and public discourse is always variously controlled by various establishments which maintain their own interests. Probably the worst time for this is any time when a religious establishment is in control; thus it's hard to grasp what people in the European Middle Ages actually thought about hell. It's not much easier for the 18th century. People say what it is in their interest to say.
Dr Johnson who was I believe a profoundly honest man displayed contradictory attitudes. In his diary he seems to live in terror of death and what comes after, but in his Review of Soame Jenyns, looking at Jenyns's expatiation of the idea that the great chain of being includes the people tortured in hell and we should delight in it in the light of common reason, Johnson writes the following sentence:
He might have shewn that these hunters whose game is man have many sports analogous to our own. As we drown whelps and kittens, they amuse themselves now and then with sinking a ship, and stand around the fields of Blenheim or the walls of Prague, as we encircle a cockpit... Many a merry bout have these frolic beings at the vicissitudes of an ague, and good sport it is to see a man tumble with an epilepsy, and revive and tumble again, and all this he knows not why. As they are wiser and more powerful than we, they have more exquisite diversions...
Of course Johnson is sarcastic in the extreme because the imbecile Jenyns lacked the imagination really to see and to feel what it is his great theory might mean to others and to himself (were he capable of including himself among the unlucky, which he is not; to him they are the unchosen or as modern equivalents of Jenyns might say the undeserving or simply vicious, for both the 18th & 20th century complacent person some "other"). Johnson does imagine what the words mean; he is absolutely intent on saying there but for the grace of God go I and maybe I go there with it. Thus the terror and the rage.
One might say well why give Richardson such a hard time when Dante is acceptable, and look lots of people in Dante's hell seem to be there because they were his political opponents. One might mischievously say the Dante folks explain it all away by talking about how Dante's hell is a metaphor, not something literally to be believed in. The punishments are just too neatly contrived.
From the perspective of Richardson's mimetic fiction one might say, not to justify Dante so much as to suggest why it's so hard to take the idea that Lovelace is damned for all eternity, is that Dante does not give us such a wealth of psychological circumstance. A crime remains a crime in Dante. If you did it, you did it, never mind the motive, the social pressure, the other people. Richardson has made us see Clarissa's flaws, that Clarissa refused to marry Lovelace, that he begged her at one point, and she fled. He has made us see Morden is a murderer. And "let this expatiate" has a curious note of hope because of the human yearning in it.
How to come to terms with this? One way might be to admit Richardson is a brilliant artist and profound moralist up to a point, but he does not enter the pantheon in which we find Johnson, Shakespeare, and put who else you want in it.
Another might be to justify the eschatology in terms of the metaphor of taking the consequences of what you do. If you did it, you're guilty, and should take the consequences. There's a certain satisfaction here, but again Richardson was not a man of metaphor in this way; his own fiction takes us in the direction of relativity and utter realism and this shows us the irretrievable judgement (particularly if we're talking some dreadful eternal punishment which is physical) is beneath the dignity or hopefully humanity of anyone who scrutinizes the case and all its actors.
As John said, Clarissa forgave Lovelace in her last moments of consciousness.