I agree about the floor - it looks like bad 1970s wallpaper and distracts from the knight. The light and the figure are very well done. Maybe you could add a couple of very dimly lit figures, or objects (church furniture, for instance). You've represented a remarkable moment in someone's life, a profoundly changing internal experience. You can underline the significance of that moment by lightly sketching in some context. A dimly perceived background suggests the external world falling away as your knight undergoes his spiritual transformation: no background at all suggests nothing.