The Modal Ontological Argument for God's existence is logically valid

Addressing My Opponent's Arguments "A maximally great being is a being with all of what we would call great making properties. That's completely arbitrary and undefined."Here is the definition of great:great/grāt/ Adjective: Of an extent, amount, or intensity considerably above the normal or average. [1]So a great being would exist in possible worlds to an extent, amount, or intensity considerably above one possible world. However, a maximally great being would exist in all possible worlds because if it didn't, then a being who could would be a maximally great being, and this is all based on the assumption that the truthfulness has been established of a maximally great being being possible in the first place. My opponent mentions some "most nearly X-like" argument Plantinga apparently produced. However, this doesn't have much bearing on my argument as far as I can tell.Now, Con claims:"Since gods seem generally nasty, I'd say the greatest god wouldn't exist in any worlds. That's not a compelling argument, but it's every bit as strong as Pro's". This makes no sense, because to be maximally great is to exist necessarily because it's less great to be contingent. So the idea of a maximally great being not existing if it is possible for him to exist, is logically incoherent. Also, God being nasty is based on scripture, but this is delving in epistomology when this is the ontological argument. "if a maximally great being exists in at least one possible world, then necessarily, this being exists in all possible worlds You can't infer this from the arbitrary and undefined attribute of "greatness."" I defined greatness in this round, and will continue to do if needed. The "greatness is subjective" argument presented by opponent simply isn't very convincing. If it's possible for a maximally great being to exist, necessarily, this being exists in every possible world."P3: "If a maximally great being exists in some possible world, then it exists in every possible world."Clearly false, given that P1 is stipulated as true"Clearly true you mean, there is no way around it I'm afraid. If the being didn't exist in every possible world, then the being simply isn't maximally great. If you accept the possibility of a maximally great being, then P3 is unavoidable."No, either P3 is false or P1 is false. Since we have stipulated the truth of P1, it follows that P3 is false. Therefore the proof is not valid. You cannot have a valid argument in which the premises contradict each other." No premises does contradict each other though, pro seems to just be making up problems with the argument that simply don't exist. Since P3 clearly follows if we accept premise 1 is true, and we already agreed that the truth of premise 1 is to be assumed for this debate, then the argument is logically air tight. Parodies Con's parody fails. Xal-X would have to be maximally great in order to exist in all possible worlds. So if this being exists, then this being would be God. However, a being cannot both be God and incompatible with Gods. Therefore, this parody involves incoherence. Conclusion My opponent simply put forward a weak parody and the old "greatness is subjective" argument. These arguments have failed in the past and they fail now. If we assume the truthfulness of the first premise, then a maximally great being's existence is inevitable and inescapable. The resolution has been affirmed.Sources [1] http://oxforddictionaries.com...;