As they went out, behold, they brought to him a dumb man possessed with a devil, Mark 9:32.
One of the most persistent holdovers from the age in which it was considered cool or intellectual to make reference to Greek or Hebrew, is the almost universal usage of the word "Demon" when referring to possession by an evil spirit. If I am reading behind an author and he refers to the trunk of his car as the boot, I know that he learned that in England. Likewise, saying y'all is pretty indicative of a Southern background. Speech helps to identify us.
No one who learned his doctrine out of a King James Bible would ever refer to demon possession because the word is never used in a King James Bible. A man using that phrase waves a big red flag that he learned his doctrine from commentaries. The bible believing world is starved for men who gained their knowledge and formed their doctrine from the word of God itself. Disguised within our midst is a cadre of men who wave a King James Bible but have never submitted their doctrine to it.
The use of the word demon is a desire to second guess the King James translators when they translated various Greek and Hebrew words. The common cry is that there is only one devil who has demons for his angels. Perhaps to a person who was schooled in Greek thought, could read, speak and write the language like a native (you don't know any such person), there is a distinction between different Greek words underlying our English text. The problem with that thought is that when King James assembled 54 such men, they agreed unanimously that there was no distinction between the two Greek words even though the underlying Greek text appeared on the surface to use two different words with two slightly different meanings. Perhaps Jesus saying, Have not I chosen you twelve, and one of you is a devil? John 6:70, persuaded the translators. In that verse, the underlying Greek word is the same word that bible correctors swear is never plural, and yet Jesus didn't say "the devil", he said "a devil".
That of course brings us back to a truth that forever vexes the greekifiers. Jesus didn't speak Greek. John recorded him in Greek. If you don't believe that a translation can be inspired, then you can't believe that the Book of John is inspired since John quoted Jesus in Greek. This is one of the reasons that I don't really care what the Greek said any more than a person should really care what Jesus really said in his native tongue. The Holy Ghost can speak more than one language. He speaks English rather well and the King James Bible is living proof. The Holy Ghost doesn't believe in demons and neither do I.