Not according to Mattew 18. The only thing James caveat shows is there are obviously mitigants associated with the promise that are not explicitly enumerated in the Biblical text; which is a position I wholeheartedly agree with.
Now, is there anything in the context of this statement to indicate that Jesus means that if we ask for a million bucks, they will miraculously appear in our bank accounts...
I dare say you have the shoe on the wrong foot. It would seem to me you have to prove why it wouldn't show up, even with James' expansion on the promise, with the understanding that the supplicants know they can't spend it on their own pleasure. Yes, in a manner of speaking I'm asking you to prove a negative, but I'm not contending this is a promise in the conventional sense of "I promise to give you a cookie." As I understand it, you are.
Besides, insofar as this discussion is concerned, it's irrelevant--regardless of what other authorities you or I might consider to be valid, the Scriptures are our mutually accepted source of authority, so it behooves us both to develop our comments and positions from that middle ground if we're going to have a meaningful conversation.
In this case, I must disagree. If Sola Scriptura were sufficient, we wouldn't be having this discussion as the point of contention would be non-existent. I wholeheartedly agree with the authority of Scripture. Nevertheless, I contend "rightly dividing the word" is much more problematic: certainly more so than cursory readings would indicate. That being said, I specifically disavow any gnostic overtones that might be infered.
I think for purposes of this discussion Scripture itself and common experience should suffice.
Now, returning to the issue of Matthew 18, why should I have to prove that the money wouldn't show up? Or that it would? You've not yet demonstrated that the context makes this statement a blank check. Until you do, why should I have to defend any proposition based on the blank check theory? You're the one claiming that's what it says, not I. Prove your premise.
Now, is the believer's authority over demons absolute? No, and I never claimed it was. There are certain things that we overstep our granted authority if we order them, like trying to command a demon to the Abyss before Judgement Day (which even Jesus didn't do), or commanding them for our own pleasure instead of casting them out to reclaim ground from and tear down the strongholds of the Enemy--that would be using the name of Jesus for sorcery, which is clearly forbidden by Scripture. And as I've already pointed out, there are rules, like never trying to deliver someone who isn't a Christian or against their will. Which is why I said in my previous post that you were partly right.
But that doesn't diminish Christ's promise that all believers would have authority over demons. It just means that our authority is still subject to a higher authority, that being His.