In my experience and hence opinion, they are not talking about the same kinds of beings.
This is the trouble with a generic word like “demon” it can mean a lot of things and get applied to mean anything from ghosts, fae, addiction and emotional-mental disorders, to astral parasites to fallen angels. These are all different things and need different approaches, so the word demon become ignorant and dis-empowering. In JCI religions you are not supposed to figure this out for yourself, you defer your will to a pastor, priest or other religious leader and do as you’re told.
So if you’re going to work with them on your terms, you need a better framework and language to be more discerning. For me, the kinds of entities that cause possession, bad luck, and sometimes unwanted behaviors or make additions worse, are called “parasites”.
A parasite is a classic “demon”, it’s never ever going to tell the truth, or do anything good for you. They lie, including about who they are, if they can speak - most can’t and just hiss or growl at you.
The only think you do with a parasite is banish it or better yet, kill it. On this score, the exorcists are spot on.
Where we diverge is in assuming that the entities that like humans and are beneficial for us, are bad because they got the label “demon” too. Fallen angels are still angels, the same species, the same skills and intelligence. They got “demonized” as was normal for entities on the wring side of Christian religio-politics because the Christian god, according to the humans in power, didn’t want then teaching humans skills, like agriculture. Personally I think skills are good and I think dimly of any one trying to keep people ignorant - there’s never a good reason for that.
So the “demons” that help are are not demons at all, that’s political bullshit for the most part, and if you talk to them yourself, you can make your own mind up.
Bad things won’t happen unless you fail to keep the parasites out, and ask for bad things to happen. Working with fallen angels for good doesn’t bring bad things.
You’ll want to get your spiritual hygiene sorted out, and start work on developing your astral senses.
Then when you can know you have a decent chance at avoiding impostors and parasites then try the first contact guides we have on here.