It could be something as simple as a draft or an uneven settling of the house that causes the door's on the closet to tend to open up. Don't get the heebie jeebies right off the bat. Try checking to see if the frame is level, if so then hold a candle in the closet and see if it flickers or use smoke (could use a match blow it out and use that smoke to see if there is a draft). If that is not it either then try simply screwing in a hook and eye type easy instillation latch. it will keep the door closed.
If the door is opening after all THAT...... call the church and....
If the door is opening after all THAT...... call the church and....
