Dr. Su`ad Ibrahim Salih, professor of Islamic Jurisprudence (Fiqh) at Al-Azhar University, states the following:
Indeed, Islam is the religion of altruism, true love, and cooperation on that which is good and righteous. We implore Allah Almighty to gather us together under the umbrella of His All-encompassing Mercy, and to unite us together as one man. Allah Almighty says:
(The believers arenot else than brothers. Therefore make peace between your brethren and observe your duty to Allah that haply you may obtain mercy.) (Al-Hujurat 49: 10)
Focusing more on the question in point, I can say that there are forms of expressing love that are religiously acceptable, while there are others that are not religiously acceptable. Among the forms of love that are religiously acceptable are those that include the love for Prophets and Messengers. It stands to reason that the love for Allah, and His Messenger Muhammad (peace and blessings be upon him) should have the top priority over all other forms of love.
Islam does recognize happy occasions that bring people closer to one another, and add spice to their lives. However, Islam goes against blindly imitating the West regarding a special occasion such as Valentine’s Day. Hence, commemorating that special day known as the Valentine’s Day is an innovation or bid`ah that has no religious backing. Every innovation of that kind is rejected, as far as Islam is concerned. Islam requires all Muslims to love one another all over the whole year, and reducing the whole year to a single day is totally rejected.
Hence, we Muslims ought not to follow in the footsteps of such innovations and superstitions that are common in what is known as the Valentine’s Day. No doubt that there are many irreligious practices that occur on that day, and those practices are capable of dissuading people from the true meanings of love and altruism to the extent that the celebration is reduced to a moral decline.