I took a car load of teenagers with me to the drive-thru at McDonalds. We all had brought some money so we could pay it forward. After paying for about 3 cars, one at a time and looping through repeatedly, the kid at the register asked why we were doing it. We said "We love Jesus and we love people. We just wanted to bless someone tonight". After hearing that he refused to take our money without first clearing it with his manager. She also asked why we were doing it and we told her the same thing.
She gladly let us continue to pay for people. The act of love can be received well; insert a figure of a religion in there and sometimes people can back off and be cautious (depending on their viewpoint or personal experiences).
It continues to be a memorable night for me and those teenagers I was with.