You don't need to be of strong faith to appreciate the tranquil atmosphere of Anglican Cathedral of St. John the Baptist. Ask when the next mass is scheduled or when it's open for general viewing.
You're spoiled for sightseeing choice when staying in Downtown St. John's. Anglican Cathedral of St. John the Baptist is a great place to begin here, but there are lots of other worthwhile places to experience. Memorial University of Newfoundland, The Rooms, and Avalon Mall are near the principal church and will round out your day nicely.