Some popular Christian bumper stickers include the shape of a fish on a single color background, one that says "3:16," one that says "Proud of my conservative values" and another that says "One nation under God" with the American flag displaying a white cross instead of stars. These bumper stickers are available online at CafePress.com to buy, as of 2015.
A bumper sticker with a fish refers to all the religious overtones of the fish in scripture. This includes Jesus feeding the multitudes with two fish and bread. Also, Christ was a fisher of men. The fish symbol was also a way for Christians to reveal themselves to each other in ancient times.
A bumper sticker with "3:16" refers to John 3:16. In this verse, Christians find that Christ died for their sins and made a way for them to ascend to the kingdom of Heaven after their deaths.
The bumper sticker printed with "Proud of my conservative values" announces a person as a conservative Christian who takes a strong conservative stance on hot-button issues. In many cases, these bumper stickers are bought by the conservative right.
"One nation under God" on a bumper sticker refers to the same phrase in the Pledge of Allegiance. The inference here is that the founding fathers wrote the Pledge, and America is a Christian nation.