The logic of the argument is not solid because if the three points you cited above can good enough proof of the existence of a god then I give you this:
1. If objective moral values and duties do not exist, then ironman does not exist.
2.Objective moral values and duties do exist.
3. Therefore, ironman exists.
1. If objective moral values and duties do not exist, then ironman does not exist.
2.Objective moral values and duties do exist.
3. Therefore, ironman exists.
Disclaimer: I am only responsible for what I say, not what you choose to understand.