A Jewish man decides his son isn't religious enough, so pays for him to go to visit Israel. However, when the son comes back, he says he's now a Christian.
The father goes to his friend in exasperation to explain the situation. His friend says, "That's funny, I sent my son to Israel last year and when he came back he also said he was Christian."
The two men decide they should speak to their rabbi about this, but when they explain their situation, the rabbi says, "That's funny, I sent my son to Israel two years ago and when he came back he also said he was a Christian."
The three men decide only God can have the answer to their shared conundrum, so they pray. The rabbi says aloud, "Dear God, all three of us sent our sons to Israel and all of them came back a Christian."
After a brief pause, God's voice booms down, "That's funny…"