God's rules for testing other gods:
"Present Your case,"" says the Lord... ""Tell us, you idols, what is going to happen...declare to us the things to come, tell us what the future holds, so we may know that you are gods. Do something, whether good or bad, so that we will be dismayed and filled with fear. But you are less than nothing and your works are utterly worthless; whoever chooses is detestable."
- Isaiah 41:21-24
God's rules for testing God:
"You shall not test the Lord Your God."
- Luke 4:12