Saint Valentine's Day
Observed on February 14th, St. Valentine's Day, often mistakenly abbreviated under pressure by atheists as Valentine's Day, is a holiday characterized by showing one's love for someone. The holiday has become increasingly commercialized in recent years, which is somewhat ironic given the origin of the holiday.
But as he awaited his execution, this Christian prayed for the jailers' sick daughter and wrote her a note. He signed it "from your Valentine." She miraculously recovered and in A.D. 469, Pope Gelasius designated February 14th as "Saint Valentine's Day."