(Haaretz) — The Jewish religion views participation in non-Jewish religious practices very seriously. In fact, the first three of the Ten Commandments all essentially revolve around the same issue - idolatry is forbidden.
Furthermore, the Mishnah and the Talmud devote a full tractate to idolatry - Avodah Zara - going over the intricate details of what constitutes idolatry and what doesn’t and how Jews should conduct themselves in their relations with gentiles: i.e., in such a way that not only are they not worshiping other gods, but do not seem to be worshiping or assist others - even gentiles - in worshiping idols. According to the Mishnah the punishment given for idol worshiping is a sentence of death by stoning (Sanhedrin 7:4).
During the Roman rule of Palestine in the Second Temple period, the Sanhedrin stopped sentencing persons to death, apparently as this was only the prerogative of the Roman state. Since then, the sentencing of Jews to death for religious infractions is not practiced and the punishment is believed to be carried out by divine retribution.
So idol-worshiping is a very serious matter and if taking part in Valentine’s Day is a form of idol worshiping, then it is definitely forbidden by Jewish law. But how do we determine this?
Unfortunately the Bible, Mishnah and the Talmud are all mute on the subject of Valentine’s Day, as this holiday is a much, much later contrivance; even a Roman precursor to it, Lupercalia – an ancient fertility cult celebrated February 13-15 – is not mentioned in these texts. Other Roman holidays are mentioned by name, however, with participation banned even in the loosest sense.
Before one can determine whether the Jewish faith sees sending valentines and giving chocolate on February 14 as a deadly sin, we must first see what Valentine’s Day is and from whence it comes.
There are several early martyrs called St. Valentine. The one venerated on February 14 is Valentine of Rome, who was martyred in 496 C.E. Hardly anything is known about him other than the fact that he was a priest and that he was buried at the Via Flaminia. His saint day was documented very early on, but was taken out of the official Catholic calendar in 1969, due to a lack of information about his life.