The Moral Argument for God

[Mudhammam]

I'm not sure if this is the right forum for this discussion, but here goes...

I've been looking at arguments for and against the existence of a "supreme being", and I'm focused on the moral argument at the moment. There are numerous versions, but a simple wording of it looks like this:

1. If objective moral values and duties do not exist, then God does not exist.
2. Objective moral values and duties do exist.
3. Therefore, God exists.

The logic of the argument is solid, so any disagreement must involve the definitions of the terms, one or more of the two premises themselves (of course), or both.

So, what do you think about this argument, and how would you go about dismantling it?

Thanks.

What is the relationship between objective moral values and God, and why does the existence of one require the other?