Puternut,
I gather from that, that Adam was created with a perfect body, but didn't have eternal life in him, UNTIL he passed the test.
I think that the more correct way to think of it is like this: Adam would have lived for as long as he was allowed to partake of the tree of life. He was already partaking of the life-sustaining tree of life, regularly, as I've already established up above. Can it rightfully be said that Adam once had "eternal" life? Yes, I think so, but it was based on a *condition* ... the condition that he remain obedient to his Creator. Likewise, even those who succeed in passing the test at the end of the 1000-year reign of Christ will have "eternal" life (life not threatened by death due to old age), but their continued existence will always depend upon them remaining obedient to their Creator. In other words, "eternal" life is nothing more than continuous life that has no end ... UNLESS the person were to at some point lose his love of righteousness and therefore become disqualified for any further opportunity at life.
So, perhaps one was poisonous, and the other had properties in it that would allow him to live eternally.
I concur with what you say about the tree of life, but I don't believe it's necessary to think that the *other* tree's fruit was poisonous. Of course there are person's who would argue that if we assume that the one tree had life-sustaining properties in it, then to be consistent the *other* tree had to have something in its fruit that would bring on death. But, does this necessarily have to be the case? Is it not possible that the *other* tree, although a real tree, was simply placed there for the purpose of representing Adam's not being worthy of life if he ate from it?
But why god would 'test' his creation, is puzzeling.
It's a simple thing, really. There's nothing more precious than the gift of life. "Eternal" life should not be the possession of any who do not qualify for it. Would you really want to live forever in a universe that was inhabited by people who practice vile things? Those who aren't able to pass the "test" simply won't be allowed to live any longer. Though sad in a way, it's a necessary thing.
The 'tree of knowledge of good and bad', was right in the middle of the garden. And they would walk by it daily to gather other fruits. It's like telling someone you cannot do something, and holding the temptation right in front of your nose. That is something that doesn't do well with me. Any father would not do that to his children.
Personally, I would say that a Creator that would NOT require obedience from his children would be an incompetent God. It's God's purpose to have peace and tranquillity flourish throughout the universe of his making, and it's simply not possible for that to happen unless those who will inhabit that universe are WILLING to practice what is right.
What exactly changed in Adam, I don't know. All I can think of is DNA structure changes.
Absolutely nothing changed in Adam, other than the fact that his body began to degenerate due to his being shut off from having the life-sustaining fruit from the tree of life. Without the ingredients of that fruit, Adam would begin to "die".
Schizm