Was Adam created immortal?
Adam was created for all practical purposes immortal; he was made incorrupt with no corrupt cells and would not have had to die. He had everything in place to live forever, but this was potential—God knew he would not, so it was not guaranteed.
Les teaches that Adam had tremendous intelligence and perfection, with everything going for him. He was, for all practical purposes, immortal. He wouldn't have had to die. He was made incorrupt—there wasn't a corrupt cell in his body. Everything was put in place that he could have lived forever. But Les emphasizes this was only his potential: 'Now I say could have. That was his potential. But what did God also know? That he wouldn't.' So Adam's immortality was a real possibility, not an absolute certainty, because God knew he would not fulfill it.
And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.
And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.