Q: What does The Urantia Book say about hell and judgment day?
A: The Urantia Book does not teach the existence of a place called “hell.” There is no place of eternal fire for the erring children of God.
Instead, the Father has created stopping-places in his Universes for the mortals of time where we go forward in progressive steps. On these worlds—the “many Mansions” that Jesus told us about—we are helped to overcome the debilitating deficiencies that may have prevented us from becoming all we could be in our life on Earth. Among these are the harmful influences that were a result of the The Lucifer rebellion and the Default of Adam and Eve
However, one still has to be careful about taking forgiveness for sin for granted:
Sin is potential in all realms where imperfect beings are endowed with the ability to choose between good and evil. The very conflicting presence of truth and untruth, fact and falsehood, constitutes the potentiality of error. The deliberate choice of evil constitutes sin; the willful rejection of truth is error; the persistent pursuit of sin and error is iniquity. (54:0.2)
Sin is a deliberate choice of evil, and should be avoided at all costs, as it can become a habit, hard to break. Of course, we all fail from time to time, but as long as we do not regress into iniquity—”the persistent pursuit of sin—” we can be pretty much assured that we will one day go to the Father’s heavenly Mansions to begin our ascending life.
About “judgment day:”
Jesus said: “Do you not perceive that, when each of you is called to lay down his life struggle and pass through the portal of death, you stand in the immediate presence of judgment, and that you are face to face with the facts of a new dispensation of service in the eternal plan of the infinite Father? What the whole world must face as a literal fact at the end of an age, you, as individuals, must each most certainly face as a personal experience when you reach the end of your natural life and thereby pass on to be confronted with the conditions and demands inherent in the next revelation of the eternal progression of the Father’s kingdom.” (176:2.7)
Jesus was talking to his apostles about his second coming, and why they should not be as concerned about that as they should be about the conditions of their souls and their spiritual growth. When we pass through the death experience, we will certainly be face-to-face with a whole new life and new possibilities for progress in the Father’s ascension plan. But we will definitely not be faced with hell—even if we have not been as good as we wish we had been.
In the unlikely event that any soul definitely decides that s/he wishes to reject the Father’s plan and refuses to accept the Father’s mercy, that soul will simply be extinguished—as if it had never been. But I find it difficult to imagine that anyone on this earth could make that final decision. We will be given ample opportunity to express our deepest wishes at some point in our eternal career, and it seems unbelievable to me that anyone would choose not to go on, but I guess it could happen.”