You are confusing a physical death here with a spiritual death or separation from God. The "soul that sins it shall die" is not a physical death. And the free gift of life in Christ is not a physical life.
The word "soul" has greater meaning, including the flesh body.
But you are still blurring the line between flesh and spirit. Yes, the spirit of all who are born died when Adam and Eve sinned--we are the children of that sin. And yes, the gift of eternal life is spiritual. But clearly, the flesh dies...which is that spiritual death being made manifest. So, the confusion is you including in what occurred in the garden, with what occurs in
this world, which is to say: death.
What shall we say then, that the physical flesh body sins, or the spiritual--the soul? What is written in the greater volume of scripture, is that
what was, was first spiritual, and what was made manifest was natural (physical), "and afterward the spiritual." But death came to the flesh by sin, and the soul although apart from God for a time, did not die--but without the flesh was offered the free gift of salvation and eternal life through Christ.