Do you know that "scrooge" means "MISER" in dictionary?
Scrooge becomes a true christian at the end of the play. The ghosts who visit him are not real. They are all in his mind. They show his deeds in the past, present and what would happen in the future. Future is nothing but an extension of the past. If you want to alter the future, alter the present. To get out of the vicious cycle of sin and punishment, one has to do "mankind's business".ie, charity, mercy,love etc. All the characters in the play are instrumental in bringing about a spiritual metamorphosis in Scrooge. Travelling in time is another aspect of interest in the play-The TIME MACHINE theme.