The ontological argument and presuppositions

I don't know why I am bummed about it. I really shouldn't be but I am.

One of the first proofs of God's existence that I had been exposed to was a rationalist one put forth by Descartes which fell under the category of an ontological argument. Basically it says that God is a being that holds all perfections and that existence is a perfection so God must exist. That's all well and good, but it suffers from a variety of issues I am afraid. Most of the issues can be overcome to one degree or another, but there is one that I think makes it just a bad argument from a natural reason or a rationalistic perspective: the definition of existence as a perfection.

In order to hold that it is better for there to be something (existence) rather than nothing (non-existence) I would have to approach the argument with a certain presupposition, namely, one that espouses a Biblical worldview or some other one that holds that belief. Believe me, I am a firm presuppositionalist as I see that as the only way to even approach any type of epistemology or knowing how we know. I know that there are lots of people that are not presuppositional in their perspective and I would love for there to be a point of connection with those people that did not entail talking about what they bring to the table as they figure out what is true or not.

But that's just me. I like cosmological arguments the best anyway as I look at trying to show that God has to, necessarily, exist rather than have faith that the universe has always been here. Again, though, there are presuppositions there that I cannot ignore. Maybe (actually I am quite sure) that it is just my flesh that kicks against all of this rather than embrace it. I am a creature after all and neither a creator nor master of anything. That should bring me comfort, right?

I don't know why I am bummed about it. I really shouldn't be but I am.