Saints and other sacred human figures in our dreams often appear as heralds of benevolence or as the "morality police." While many times these are positive dream experiences, the dreams can also leave a feeling that perhaps you are not doing all you can to be an agent of good in the world. The dream may be inspiration to involve yourself in a particular cause through hands-on work or financial donations.
The moral side of the dream is often a judgment on current lifestyle choices. When your psyche is in conflict between the desires of the id and the restraint of the superego, the superego can marshal symbols of judgment to strengthen its position. Often these will arrive under very peculiar circumstances. A dream of sexual desire may suddenly find the object of its desire cloaked in the garb of a priest, pastor, rabbi, policeman, or a particularly strict third-grade teacher you may have had.
If a saintly figure in your dream suddenly turns into a demon of some sort, or begins to resonate emotions that are non-traditional from such a figure, perhaps it is a sign that you need to check your morals concerning a situation in waking life.
Does the saintly figure in your dream appear as a helper or emotional benefactor, or does the character seem to be coming down on you as a law-enforcing authority figure?