I'd like to see someone make one of those sign generators for these billboards, so I can make some parodies, which these are just asking for. These billboards aren't as lighthearted as some of the church marquee signs (like this one, for example, which suggests a God who has mellowed considerably from the one who sent the plagues of the Exodus).
Here are some ideas for better content:
Stop putting words in my mouth. --God
If I existed, I'd communicate directly to all people in their own languages in a miraculous manner rather than through billboards put up by people pretending to be me, just as parents pretend to be Santa Claus. -- God
Please post further suggestions in the comments. (And if somebody writes or finds a billboard photo generator, please let me know.)