I think you have done justice to the ontological argument for the existence of God in very few words. I say this because I have been looking into St. Anselm (and others) because of a study
you have inspired. I am hoping to publish the results of this study on my
blog soon. Indeed, you have just inspired another idea for an article for my blog.
I find that
any argument for the existence of God to be full of holes. This is why I decline to argue for His existence anymore. Because ultimately, it comes down to where one is going to put his faith. I have no problem with placing atheistic/naturalistic arguments against God on the same plain as arguments for Him. This is because NO ONE is ever going to prove their position. ALL arguments whether for or against have holes in them. Instead, I'll fall back on Hebrews 11:6 :
And without faith it is impossible to please God, because anyone who approaches Him must believe that He exists and that He rewards those who earnestly seek Him.
If I am mistaken in this, I'll never figure it out because I won't be around to say, "I was wrong." Take note: this IS NOT my rationale for choosing to believe in God. It is my rationale for not arguing for His existence.