Valentine's Day derives from a Christianized version of a pagan holiday. Just as the Christians stole Christmas and Easter, from the pagans, they took this celebration from the Roman pagans.
If you do not adhere to Christology, then why would you want to celebrate to the name of a Catholic Saint who had nothing to do with the original festival?
The name "Valentine" comes from one of two Christian martyrs of the 3rd century. One describes a Roman Christian martyred during the persecution of Claudis II, the other, a bishop of Terni who got martyred in Rome. (Most Christian celebrations have a preoccupation with death and martyrdom.) There occurs several versions of the Christian legend but no one knows the truth for sure. Probably at least one of them did live and died, but we have little else to go on.
In pre-Christian Rome, people celebrated Lupercalia, a Roman holiday that took place during the ides of February (the 15th). They believed that the goddess Juno Februata (where the name February comes from) inflicted her "love fever" on the young and unwary. The fertility festival of Lupercalia (in honor of the pastoral god Lupercus) involved sexual excesses such as running around nude. The festival included the sacrificing of a goats whereupon women would be whipped with the hides of the animals just slain. Women would line up for the men to hit them, believing that it would make them fertile.
For years the Christian church tried to suppress the festival of Lupercalia. Interestingly, the Church did not object to the festival for its love celebrations but for the pagan beliefs that rejected the Christian god. In 496 C.E., Pope Gelasius abolished Lupercalia, and later the celebration of Valentine, named after the legendary St. Valentine, was established. Cupid was recast into a cherub, and the Lupercalia festival continues much as it had before, but without the sexual excesses.
So the idea of Valentine's Day did not originate from Christianity, but from "heretic" pagans. Praise Juno! (But please, lets bring back the sexual excesses.)
The Dark Origins Of Valentine's Day