Great cathedrals, require great lighting
© Bob Blanken
Great cathedrals make for great images. The exposure in any auto mode, including Aperture or Shutter priority, should have an exposure compensation of -2, using ETTL or center-weighted. Bracket up/down 1 stop. In manualmode, just under exposure 2 stops, and bracket. You get dark, rich shadow areas and the highlights should be right on.
© Bob Blanken
Use that tripod you should be taking with you. Night time is a wonderful time to capture images. Bracket your exposure. Use the incandescent WB setting or better create a custom white balance.