Here's my 1.3 cents on the subjects.
Everyone that's heard me rant, already probably is fully aware that I'm not a big fan of labels. And the same holds true in this case. Tossing the label "Demon" onto something conjures up (pardon the pun) a whole host of imagery and stigma. As was mentioned, almost instantly its pushed into an area where certain faiths start to take over. I personally am a Christian, but I also think you let a baker cook bread, and a barber prim beards and hair.
I personally don't believe in Demons in the sens of what we see on TV. Do I believe powerful and negative spirit entities exist, oh most certainly. But I don't think they are the classic "Demon" which we've seen and heard so much about in the last few years. That is not to say though that they do not command just as much caution or precaution, I just don't like tossing the label out there because it can tend to push someone down a path of ignoring avenues which otherwise may prove helpful.
Without getting into an entire theological argument of "I'll see your priest and raise you two pastors", if you look at the texts which are the basis of the concept of theological demons you will almost consistently see attempting to remove such a Demon from a person who does not fully believe, and claim (and not just in word but in life) the power and lifestyle of the theology, the entire practice of casting such a Demon out is futile and in most cases will result in such a demon coming back with a bunch of his buddies and nesting. So, even if you do subscribe to the concept of Demon's, I would urge caution in being too eager to pursue that route.
If you look at how many persons and critters have passed away on this earth since the beginning of time, its no small wonder that there are still some very powerful and primal energies left here in certain places. And if they are not treated as such I personally believe you could potentially open up a world of hurt. We often caution about opening "Doors" or playing with fire. When you do so, you make yourself visible and in some cases even attract attention. Some things you may attract are not bad, but you never know when something not so nice may take a shine to you. So caution and some common sense can go a long way. You would play hopscotch on a cliff blindfolded without someone there to help you point the way and make sure you're not approaching danger. Same holds true when delving into the paranormal.
In my personal opintion (and this is just me) I also think that when we consider what may be out there, we have to also look beyond just our world. Since space and time don't have the same physicalities and restrictions in the spirit world, its not unconceivable that something from another world may not find its away here, attracted by some beacon, energy, or cataclysmic event.
So to wrap this up. Demons -- not so much. Other things which are just as scary, dangerous, or dark -- most certainly.
Just my thoughts, and I'm stick'in to em!
CrysalCross (Rob)
ParaFlunky - extraordinaire