I am looking for an old black and white movie I saw many, many moons ago, but I cannot remember what it called or who is in it! The premise is that a group of passengers on a ship are lost and apparently sailing adrift in thick fog. They are, unknown to them, set a series of tasks to test their character. The gentle person who seems to have the job of overseeing all these folks is a minister of religion. In the end we discover that they have all died before the main action of the film started. The minister is presumably, God, and the ship is, presumably, purgatory. This, maybe, doesn't sound such a great film put like this, but I fondly remember the gentleness and charm of the film and would love to track it down. Any clues, anyone?