Not true, you have this backward, the RCC instituted All Saints day to combat the pagan explosion of followers of this demonic celebration. Samhain( pronounced - sow-in) Was the lord of darkness and was the the highest worshiped in Celtic belief. The Celtics 2000 yrs. ago in the area known today as Ireland celebrated the days of darkness- fall is the beginning when the days of light are shortened and darkness is longer.
The worship of Samhain included: food, animal and human sacrifice. Skulls of victims whether human or animal were left out with a candle in them to direct the spirits of the dead away from Samhain who pursued them. The people hoped the blood sacrifice given would satisfy the demon and he would let the dead rest. The food sacrifice and other gifts of the harvest were to satisfy the spirits of darkness to prevent mischief that the pagans believed was from these spirits. This evolved into Halloween or Hallowe'en .
The pumpkin came to represent the skull of the victim. The trick or treat derives from the acceptable gift of the giver to prevent an ill response from the demon. On this day people do as the ancients did. Glorify the dead and the spirits of darkness and entertain lying spirits. The Celtics also dressed as the spirit of the dead and performed ritual dances to communicate with spirits.
However, unless you are into the occult and witchcraft , the only death occurring is the dying of the light of the soul. To most this does not seem problematic. People use every excuse possible to try and justify its celebration. Somethings are elementary and people know the Christian view of it is right. Anyone with eyes and commonsense can see what is being glorified on Halloween. Denial does not make it something it is not. Why do you think Halloween is the witches and those of the occult's" HIGH DAY". It is their day as Dec.24 is to Christians. Except Satan is glorified.
Rev.3:15-16 " I know your works: you are neither cold nor hot! So, because you are lukewarm, and neither cold nor hot, I will spew you out of my mouth." The entwining of pagan with Christianity is not true Christianity and people are only fooling themselves . Celebrating Halloween is another type of lukewarmness that Christ hates. You do not have to agree, but I will not censor the truth of God's Word for popular opinion.