To appreciate and be thankful for any benefits, advantages, or opportunities one are afforded, no matter how minor or inconsequential. Used particularly in the midst of an otherwise difficult, frustrating, or unfortunate situation or circumstance. My car's air conditioning stopped working two hours into my cross-country road trip across America. The radio still worked, though—thank God for small mercies. Our son's accident left him without the use of his right eye, but he still has the use of his left one, so we're thanking God for small mercies.