In the genesis story the serpent tempted adam & eve to eat from the tree of knowledge.
wouldnt it have caused more damage if they were to eat from the tree of life instead?
another hole in the story?
In fact no. Genesis doesnāt actually say that they were originally forbidden from eating from the tree of life, but even if they were there is no reason to think it would have done more damage. And even if it would have done more damage, it doesnāt actually make a difference to the story, since it was the act of disobedience that did the most damage, not the effects of the tree. Which may or may not even be literal. But assuming itās literal for the purposes of discussion (for even if itās not, what happened happened with the same effects as if it were):
First, God could have, had He so chosen, brushed off or reversed any of the changes either tree would have caused. Had they eaten from the tree of life, God could simply have removed the effects. Now, it is fair to assume based on His actions that He did not want to, He did not want to override the consequences of Adam and Eveās choice.
But He could easily throw a couple immortals out of a garden without removing their immortality, as could any angel God tasked with so doing. Easier than killing a fly with a flamethrower. We are no threat to God.
As mentioned, the bad thing about eating the fruit was not so much that they gained the knowledge, which they may well have gained eventually anyway, but that they disobeyed God and fell from a state of grace. Any sin would have done this. At the time, there was really only one sin available to them that I am aware of, but they did it. That the sin related to learning more about good and evil is less important.
Fallen immortals, or fallen mortals doesnāt matter, weād still be fallen. And that was the worst part of the fall, not which tree they ate from.
But you could argue that the tree of knowledge had the worse effect in any case, because it makes more types of sin possible. A person who is innocent of knowledge cannot sin, in gaining the knowledge of what was good and bad before being able to handle it they equipped themselves with ability to offend God without the tools to refrain from doing so. This could be said to be worse than a couple of mostly clueless immortals wandering around the planet. Again, Satan was not interested in bringing about threats to Godās power - thatās impossible and even he has to know that - but to cause there to be lots of sin and turning from God.