I will say this very tenderly...
But God's church truly knows no denominations. He won't have a "baptist" corner and a "pentecostal" corner, etc. However, all that are in his church will be bought with his blood, possessed of his spirit, and sanctified by his word.
I will note that most all denominations do stem from the Catholic church. In my personal opinion, the Catholic church is indeed full of evil and wickedness, and I do see scriptural evidence that they are the "great whore" of Revelation.
Now, here's the part that some people will find issue with. I am a firm believer in the oneness of God, and that God is in no wise "triune". You can dispute me in this, but you will not convince me because I feel that I have the Word and the Spirit behind me on this. If the doctrine of the trinity was so important to the church, why isn't it in the Bible? Why doesn't the Bible come right out and clearly say that God is three? It says that "there are three" but it also says right then that "these three are one". It plainly says that "God is one", and you can easily see how the name of the father, son and holy ghost is Jesus, and it states that Jesus is the image of the invisible God, and Jesus is the flesh of God.
In short, I don't see the doctrine of the trinity anywhere in the bible, and in fact, the first place I see it at all is around the time the catholic church pops it's head up, around 300AD. That is also, you will note, the same time that the church get "watered down" with a ton of pagan beliefs, mary worship, etc... the holy ghost is not nessecary, and all kinds of other false doctrines creep in, much of them thanks to Emperor Constintine and his acceptance of christianity as "the popular thing to do".
Hence, many many many denominations, virtually all of them, shoot off from the catholic church... carried with them the doctrine of the trinity, with hardly any biblical proof (for such a necessary doctrine). Lutherans peeled off from the catholic church, and soon other denominations followed, with the reformation and all. But they could be considered "the children" of the dragon, simply because they are not reading the bible as it is, but carrying with it the false doctrine of the catholic church.
Therefore, my personal conclusion is that, denominations are not evil, it all depends on what you teach. You can be non-denominational and reach false doctrine (as I believe the doctrine of the trinity is), and you can be a member of a denomination and preach the truth.
I personally attend a denominational church, but it does not not teach trinitarian beliefs at all, therefore I don't see it as one of the children of the dragon, but any denominations that still do teach the traditions they have been handed down, all the way from the catholic church, may still be considered the children of the dragon.
That's my take. Hope I didn't offend anyone, but I cannot back up from what I so firmy believe. I'm not here to argue, either... that's been done enough in other forums, and quoting non-biblical texts and "what the early church fathers say" just doesn't convince me. :-P