Satan and demons

My interlocutor believes the definition of angels is incompatible with sin. He sets forth a logical argument as such: P1. Sin brings death P2. Angels cannot die C. Angels cannot sin I believe this belies a rather poor understanding of the statement that "the wages of sin is death", however apart from whether or not the phrase refers merely to physical death, there is a previous problem of whether or not this statement is applicable to angels. Paul is speaking to the Church in Rome, presumably all of them human. Revelation is meant for mankind and speaks to mankind, and just as we cannot expect references to unchastity, adultery or the use of material belongings to apply to angels who, as spiritual beings have none of these concerns; we cannot expect a statement on physical death to apply to them. Only God is incapable of sinning. This is because the rule of righteousness, of Good, is His very nature. Angels and Humans are not the essence of Good, we are rather created by God and geared towards Him. Our function in life is to know and love God and to do His will, just as the angels, and whether or our we sin by an action a thought or an omission is determined by whether or not our will is in accordance to the Good, which is outside of us. Similarly with angels: if the rule of righteousness, of good, is to be found in them then they cannot sin. If it is found outside of them (in God) then they are at least theoretically capable of sin. This seems to be what happened according to Jude 1:6 " And the angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day." Even if the argument were sound, however, this would be a challenge only to the true origin of demons, and not to their existence, which is abundantly attested to, particularly in the New Testament. Although I hope we may refer to this in more detail later on, as my partner in this debate only referred to this matter in passing, saying the casting out of demons refers to the healing of mental disease or physical illness, I will only reply in passing that the New Testament authors were sufficiently familiar with mental disease and physical illness that they could make (and indeed did make) references to them without calling them demons, identifying them by name (Legion for legionella, I suppose), having them identify Him as "The Holy One of God", or allowing the mental or physical illness to possess a large herd of pigs and drown them in a nearby lake. My opponent also mentions the different uses of the word "Satan" in the bible as adversary or diabolos (devil) as enemy, liar or accuser. This is simply not a sound argument. It would be as if someone were to say that, as the term "Son of Man" has been used to describe the human race as a whole (in Numbers, Job and the Psalms), individual men (as in Ezekiel) or to denote human frailty (as in Isaiah) then it cannot refer to Jesus Christ. The fact is that in many instances the bible refers, not to enemies of Israel or mistaken apostles, but to the "father of lies" and "murderer from the beginning". This is, perhaps a good time to turn to the testimony of the early Christians, to see how those closest in time to Christ interpreted these "personifications". It would be difficult to find any of the early Christian writers who interpreted references to the Devil as anything but literal. (I will resist the urge of listing patristic authors and their positions for the sake of legibility). The final contention against the existence of the Devil or demons is that the power of demons would entail some sort of Polytheism (a bad god and his lackeys vs. the good god and angels). This is a misunderstanding of both the nature of the Devil and of the power of demons. Take two evil people: the first of these is rather a simpleton whose evil actions were limited to taking candy from small children when their mothers aren't looking; the second is incredibly intelligent and weaves dastardly plans for his illegitimate gain and the ill fate of those he considers enemies. The second of these two evildoers would be more powerful than the first, by virtue of a greater power of intelligence. This power does not diminish the power of his Creator in any way, as he owes it entirely to the nature granted to him. In this same way the Devil and demons, former angels, owe their "power" to their angelic nature, and not to themselves. They are creatures of God and have nothing that is not given to them from the beginning. The evil they do with said powers is tolerated just as the evil done by humans is tolerated. God does not have power over evil, but neither does the Devil or demons. Evil is simply not something that power can be had over, it is the mere negation of good. God made all things, and in so far as those creatures with free will deviate from His will, they engage in evil. Just as it is with humans, so it is with angels.