The Staring Match - S9.E36

Set in a small ranch town that is suffering from drought, townspeople gather to pray for rain in the schoolhouse. There is a knock at the door and a man dressed all in white greets everyone by name. He says that his name is Mr. White and that he has been sent to help them find a well. Then another knock at the door reveals a man dressed all in black, who claims that his name is Mr. Black and that he is an angel of the Lord sent to help them also. Not knowing which man to trust, the dilemma is resolved by a ""staring match"" between the two men. In the end, the angel is revealed and water is discovered.