Well, this is now off topic. But I have presented the argument before and received the standard replies (that is, say, it has the fault of having premises or of actually entailing its conclusion - that kind of thing, standard fare from the internet educated). This is the argument (each premise is either self-evidently true or is implied by self-evident truths):
1. Imperatives of Reason exist
2. All of the imperatives of Reason have a unitary source
3. Existent minds and only existent minds issue existent imperatives
4. Therefore, there is a single existent mind issuing all of the existent imperatives of Reason.
5. The existent mind whose imperatives constitute the imperatives of Reason will be omnipotent
6. The existent mind whose imperatives constitute the imperatives of Reason will be omniscient
7. The existent mind whose imperatives constitute the imperatives of Reason will be omnibenevolent
8. Therefore, the single existent mind whose imperatives constitute the imperatives of Reason is God (an omnipotent, omniscient, omnibenevolent mind).
There is, I think, no reasonable way of resisting any of those premises. The weakest premise is 2, though I believe there are numerous arguments that can be provided for it, and it seems self-evidently true, as is reflected in the fact that we do talk of 'Reason' and mean by it the source of all reasons to do and believe things.
The argument is valid, but it does not have to be. It just is. And the god - God - that it demonstrates to exist, is a person who can do anything precisely because the edicts of Reason are theirs to make or unmake as they choose. And so that being is not in any way bound by them. They express her, but do not constrain her. And as it is only by appeal to Reason that anyone could ever show that there are necessary truths - for the evidence that there are some is that Reason appears to say there are - there are, in fact, none, for anything Reason says she can not say too.