I submit this for your review as I studied this about 30 yrs ago. I have searched for links so you can research the answer in depth at your leisure as there is many many studies and opinions out there. The following are just a few I am sighting for you from my studies. I hope it helps....and if you desire more information let me know.
Bob Larson, argumentatively, one of the churches leading authority on the occult says...
“Fear hath torment,” says 1 John 4:18 (KJV). Whatever the psychological reasons for paying to be scared out of one’s wits, the real force behind such Halloween attractions is Satan. In fact, 2 timothy 1:7 clearly says that fear is a “spirit,” a demon. If patrons of fear franchises really want to be tormented by terror, all they have to do is reject God’s offer of salvation through Christ, and the devil will give them a free ticket to eternal terror. https://boblarson.org/blog/2012/10/halloween-franchising-fear/
Today, Halloween, people are looking for imaginative ways to stoke the fear factor. TV networks are featuring non-stop fright flicks. Theatrical haunted houses are trying to scare the living daylights out of paying customers with ever more gruesome and realistic horror. But trying to up the hormone rush of fear for any reason isn’t smart. God gave us our fright-and-flight response for self-preservation, not manipulation. Demons do that, and one of the most powerful evil spirits is that of Fear. I’ve often said, “If you have the spirit of fear [exposed in 2 Timothy 1:7] you don’t need any other demons.” Fear is a gatekeeper letting other demons in. this Halloween, focus on “power, love, and a sound mind,” not terror. And stay away from haunted houses, real or fake, and snake therapy. You don’t need a dose of fear to feel good. You need faith in Christ to be free from slithering spirits. https://boblarson.org/blog/
Steve Harmon, Th.G., B.S., Th.M., Th.D. says...
Samhain (holloween)is considered the most important because the veil between the world's of the living and the dead is at its thinnest point in the year, making communication easier. The souls of the dead are reported to come to the land of the living. Much more detail here http://www.ecclesia.org/truth/holloween.html
Anton LeVey head of the Church of Satan,
said "he was glad the Christian parents let their children worship the devil at least one night out of the year. "
Don and Phyl Tobias
It is interesting that the ceremonies for honoring the dead in the Fall of the year, Oct. or Nov., were known to all ancient cultures. The Assyrians, Hindus, Persians, Chinese, American Indians, natives of the islands of the South Seas, as well as the British, Irish, Scots, etc., all believed that this was "the time of ghosts" as the dwellers in what is now Britain called it. In Genesis, chapters 6 through 8, we read the story of Noah's ark and how God saved just 8 people, Noah, his wife, his three sons and their wives, out of the entire world because Noah was righteous before Him and how the rest of the population was wicked and was destroyed. This occurrence was undoubtedly perverted and survived throughout the rest of the peoples of the world as stories of ghosts, the dead returning, etc. Traditions of such similarity all over the world could not be merely coincidental. Genesis 7:11 tells us that the storm started on the "17th day of the second month." The Jewish new year begins some place near the middle of September. Thus the deluge would have occurred at the end of October or the beginning of November. More information http://www.blessedquietness.com/journal/housechu/hallween.htm
D. James Kennedy. A.B., M.Div.
Dr. Adrian Rogers three time president of the Southern Baptist Convention
As a matter of fact, I believe that Halloween is one of the masterstrokes of Satan, to make us believe that all of this is just so much of a fairy tale. http://www.sermonsearch.com/sermon-outlines/14393/devices-of-the-devil/
Just for the record I want to point out I did not comment on my thoughts as the question did not want to know my opinion but the opinion of noted experts. So I remained without comment in respect to the question.