When Christy asks where God is, he is told that god is somewhere looking down at us smiling. To me that would be more of practical if they were on earth but it is not true. C. S. Lewis says that in heaven we will be with God, this is also what the church states. It is also impractical to think that a person can create their own world in heaven, although it would be very nice to think that, why would a person want that if they are totally embraced by the love of God. When Christy meets his children in heaven they took the image of actual people that they thought their dad respected, this caused Christy to not realize that he was in front of his children the whole time. This is also impractical because it is said in the bible that we will have our bodies and they will be restored to perfection, whether that is true I am not sure but it would also be nice for that to be true.
When Christy found out that his wife committed suicide his whole world turned dark and dreary. He became angry and wanted to go find her to bring her back to heaven. He actually leaves heaven and goes into hell to find her in her little world. This to me would not actually happen, because in heaven you are surrounded by love and the only reason someone would leave is because they were selfish. The tracker that brought him there said once you go in you will be under her control and most likely won't come back. Christy ignores this warning and goes in anyways and ends up saving his wife from hell. This I believe would not be able to happen, I believe what C. S. Lewis thinks, the doors to hell are locked from the inside, we cause ourselves to be in hell. The way the movie shows us a way to get out of hell is sort of like a get out of hell card and the way the movie portrays hell is more like infinite punishment which is not what the church says. The way the Church and C. S. Lewis is hell is eternal punishment is complete punishment, which in a sense as a certain amount of time, where infinite punishment lasts forever. I believe only when a person realizes they are in hell and finds the "key to the locked door" is when they could get out of hell and enter purgatory, if it is even possible that to happen.
On top of hell being locked from the inside Christy left heaven which indicates he turned his back to God. In that case he should stay in hell because he rejected God by going to look for his wife. Also he "died" in hell and suddenly was in heaven