Happily, the JW's concept of Paradise is flawed. To the early Christians, Parardise was a place where the souls of the righteous await the resurrection. As Clement of Alexandria wrote, "After death, I think the saints go to Paradise, a place of learning or school of the spirits, where everything they did on Earth would be made clear to them." We cannot expect that men can be either saved or damned in ignorance, and many on Earth have died without having heard of Jesus or his gospel. So if they don't hear it here, they must hear it there, as did the thief on the cross.
Even the best of Christians must come to grips with their own lives; their faults, their successes, the good within themselves and the bad. This is reflected in countless near death experiences, where people undergo what's now popularly referred to as "life reviews." Those who have experienced them say it all happens very rapidly, yet they say it is extraordinary comprehensive and in places most unpleasant. Yet it's designed to purge the soul. The more wicked a person is, the more unpleasant the experience. Imagine, if you will, Stalin, Mao, Hitler, Saddam and his sons, and many, many others having to constantly relive their mortal existences, witnessing to the last detail the effects of their lives upon others down to the last niggling detail. Of watching each of their victims from the time of their births to the time of their deaths. Of experiencing everything they experienced, feeling everything they felt. And all of this through the entirety of the Millennium!
This, I think, is the fire of Hell. But as Malachi said, it will be a refiner's fire. And though the suffering is intense, it burns away one's wickedness, or sins. When one emerges from it, one is a better person. Thus, King David cries unto the Lord, "for thou shalt not leave my soul in hell."
The JWs see the atonement as restoring man to what he was in Eden, only now everyone will dress for dinner. But that would be a nightmare. Man was created to be much more than that.