Bumpersticker I saw on the way to work:

God forgives.
Rocks don’t.

I went through several theories about what this might mean.

1. Driver is a rock climber, and the statement is a meditation on his relationship with the difficult rocks he scales.
2. Driver is an environmentalist, and the statement is a meditation on the fact that, while God might forgive you for the way you abuse the planet, mother nature is a wrathful, resentful bitch who will punish and smote you mightely for all the abuse she’s received.
3. Driver is a geologist, and the statement is a meditation on his theological battles between his religion and his science.

Any theories? [Update: I should have written to Dear Donut to ask advice on this issue, because she had the answer to this bumpersticker mystery! Read more in the comments.]