“The one who imitates a nation is from among them” (Hadith)
The “celebration of love”, which is celebrated on February 14 each year, was invented by the Romans more than 1700 years ago. The Romans, at that time, were idol-worshipers. They killed one of their own people, Saint Valentine, because he became a Christian. Later on, when they became Christians, they made the day of his execution an occasion to celebrate those who were killed for the sake of love. Today people still celebrate this festival to show their love for each other.
Participating in this festival is totally un-Islamic. Unfortunately Muslims also participate in these un-Islamic celebrations. These customs have passed on to us Muslims because of our mixing freely with the non-Muslims.
Allah Ta’ala has given Muslims the days of Eid to celebrate. We should confine ourselves to these days of celebration and not celebrate with the Non-Muslims.
Valentine's Day is a Christian Celebration. We, as Muslims should not involve ourselves with the customs of Valentine's Day, like sending cards, presents, roses, etc, because we will be imitating the Christians. This is what Shaytaan wants from us. He wants us to follow the Kuffaar and stay away from following Rasulullah (Sallallahu Alayhi Wasallam).