You could also do something along the lines of:

This is the supreme being. You have chosen the wrong faith but there is still time to choose the correct path. Repent now and mend your ways.

And then just watch everyone abandon their faith and frantically switch around to what they think is the ‘right’ one.

Bonus points if you can send a follow up message 6 months later saying it was a test and they failed lol

“Everywhere except Europa. Europa’s mine. Piss off.”