A Jewish businessman sent his son to Israel for a year...

...so he could know a bit more about their culture. When he came back home, the son said:

'Dad, Israel was great! Oh and by the way, I became Christian.'

'Oh no!' said the father. 'What have I done?'

The father then went to hang out with his best friend and told him about his misfortune. His friend said:

'What you're telling me here is interesting. I, too, sent my son to Israel and he returned a Christian as well. Perhaps we should ask our rabbi.'

So they went to the rabbi and told him about their problem.

'What you're telling me here is interesting. I, too, sent my son to Israel and he returned a Christan as well. What's happened to our sons?'

After this short conversation, they decide to pray to God for their sons, and ask Him for guidance. Once they finished praying, a resonant voice from above said:

'What you're telling me here is interesting. I, too, sent my son to Israel...'