You are starting from the assumption that "god created the body and the soul" - whereas the thread starts from the assumption that god created the body:
Then is it
"Let's hypothesize there was a creator. If something designed people, or earth, or whatever, why would this mean there's life after death? I see no relationship between a creator and the existence of the soul."
You have jumped in with the assumption that god created the body and the soul - i.e. that the soul exists.
I think it is logical that, IF we were created by God, and IF the God created our body AND soul - then there would be an afterlife.
But the thread-starter is starting from the position that God only created our bodies. In this instance he is asking what the connection between the creator and existence of the soul - i.e. with no other assumptions, is it reasonable to assume that creator implies soul?
I see - I wasn't aware exactly how ridiculous this thread was but I think you are bringing it closer to my awareness.
If god created the body with no soul it would be a dead body.
To establish that this is not a scientific claim you will have to establish how life can come from matter.
In other words you might say that the idea of consciousness = the soul is a theory, but if we apply the same empirical requirements for evidence that a combination of matter also equals consciousness then it is also a theory.
In otherwords empiricism isn't sufficient in itself to establish anything either way.
I guess it might be more progressive therefore to distinguish what a soul is - so let me ask you this .....
When you say Hello to somebody, what are you addressing?