Halloween
The custom celebrated today as “Halloween” is linked to a pegan festival of the dead. An Irish-Celtic festival called "Samhain" has existed since the seventh century AD, which was traditionally celebrated on November 1st of the year. This rite should allow access to beings from another world. In Roman mythology, the gate to the underworld was opened on this day. Blood sacrifices were made in honor of the god of the under-world. Halloween is considered one of the highest days for satanists and devil wor-shipers. At the same time, this is the day when statistically the most satanic occult ritual crimes are committed.
In Catholicism we can find parallel to this the feast day “All Saints' Day”, on which ce-remonially so-called deceased “saints” (ie those people who have been declared to be holy by the popes) are commemorated. This practice amounts to a death cult, which God in turn strictly forbids to do.
The Halloween custom of hollowing out and decorating pumpkins goes back to a mythological figure called "Jack with the Lantern", who was a farrier and, according to tradition, received a piece of coal from the devil which Jack put into a hollowed-out turnip in order to have light and warmth for all eternity as an undead who was denied access to both heaven and "hell".
In the Bible, magic and sorcery generally stand for evil or anti-divinity. For this rea-son, God has forbidden us humans to have any contact with it. When people come into contact with occult practices - whether active or passive - they open themselves to the influences of the devil. They risk being possessed by demons or evil spirits that con-trol their thinking and be-havior, which means very serious threat to the possessed person and those around them.
By dressing up as witches, ghosts or even devils, which is common on Halloween, these dark powers are made attractive to people and the danger they pose is down-played. The same applies to films and music in which magic is portrayed as something posi-tive. The most serious consequence is that people are led away from God in this way, with all the consequences that this means for a person, both in this life and in view of eternity.
Sources:
Wikipedia
Encyclopedia Britannica
Encyclopedia Americana
Catholic Encyclopedia
Encyclopedia of Religion