Atheists recently drew attention by putting ads on British buses declaring, “There is probably no God. Now stop worrying and enjoy your life.”
Christian groups are responding with their own ads, which seem a bit lackluster to me:

“There definitely is a God.”
“There is a God. BELIEVE. Don’t worry and enjoy your life.”
“The fool hath said in his heart, There is no God.”

That’s it? That’s the best they could do? That may rally some passionate believers but I think the goal of the campaign is persuasion.
Come on, gang, let’s help them out. What would be our simple pro-God slogan for a bus campaign.
I’ll start the ball rolling…

“Design, consummate skill, and indefinite power in every atom.”
–Thomas Jefferson
Big bang. Big God.

Ok, I’m sure you can do better than me. Remember, these have to be short enough to fit on the side of a bus.