Some may wonder at the importance of this question but before you go away, consider this. So much of what we believe is often accepted without question. Usually our 'teachers' are people who are respected and therefore believed. This process is repeated as we in turn teach others. Usually we are cautioned against questioning the accepted dogma. (See Essay on "Air Pollution")
So, the simple question, "Were Adam and Eve Immortal?" is an exercise to demonstrate how easy it is to accept and believe what we are taught. Most folk would answer our question in the affirmative and say that only after they disobeyed did they become 'mortal' or experienced some sort of spiritual "death". Well, have you noticed the contradiction in that statement alone? To be 'immortal' means just that - it is irreversible, you can't die!
Have you ever wondered why Adam and Eve and the animals needed food? See Genesis 1:29,30 (1) Now the "Answers In Genesis" folk, who produce some wonderful material on creation claim that before the fall death was unknown, but how so? If all living creatures needed food, then death was a possibility, even if at that moment in creation none had actually died. Further, how could the concept of death exist if it wasn't known and so be a threat to Adam, yet God spoke plainly and used the word in Genesis 2:17 " . . . for in the day that thou eatest thereof thou shalt surely die". If death was unknown, some more technical description of the cessation of life would seem to be called for. That may need some further explanation but for now it simply illustrates that the cessation of life was a known event, certainly for the vegetable kingdom, most probably for the animal kingdom and was understood by Adam. It clearly did not mean instant death or for that matter "spiritual death" as is usually taught. The sentence was passed that very day when Adam and Eve were driven from 'Gan Eden' "In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art , and unto dust shalt thou return." Genesis 3:19 Death is a process. (See "A Biblical Day)
Next we note the words of God, spoken to the attendant angels, when He placed a guard on the "way to the Tree of Life" in Genesis 3:22,23 And Yehovah God said, Behold, the man is become as one of us, to know good and evil: and now, lest he put forth his hand, and take also of the tree of life, and eat, and live for ever: 23 Therefore Yehovah God sent him forth from the garden of Eden, . . . 24 So he drove out the man; and he placed at the east of the garden of Eden Cherubims(2), and a flaming sword which turned every way, to keep the way of the tree of life. I think it is pretty clear here that Adam and Eve were not immortal but could have become so, even as sinners, or at least avoided death by partaking of the Tree of Life.
Now, one more little example of how we believe what we are taught. Verse 24 above has been depicted by artists as an angelic being holding a sword with a blade of flame at the gate of the garden. The Hebrew word 'cherubim' is the plural of cherub and could have meant at least two and any number above, maybe a platoon or a company. But, the 'flaming sword' was singular and separate and clearly "turned every way to keep the way of the tree of life." Isn't the picture more accurately a number of cherub (cherubim) and a single (automatic?) device that monitors and prevents access to the Tree of Life. (See "A Flaming Sword")
One other interesting little insight, is to note the actual temptation of Eve. First compare Satan's words in 3:5 "For God doth know that in the day ye eat thereof, then your eyes shall be opened, and ye shall be as gods, knowing good and evil." with Yehovah's words in 3:22 "And the LORD God said, Behold, the man is become as one of us, to know good and evil: and now, . . ." Satan sometimes speaks the truth to deceive us.
Also, the picture is usually portrayed as the Serpent tempting Eve and after Eve had eaten she found Adam and offered the fruit to him. Well, she did, in that sequence, except that Adam was present with her all the time and permitted the act of disobedience - just read the account carefully. Genesis 3:6 And when the woman saw that the tree was good for food, and that it was pleasant to the eyes, and a tree to be desired to make one wise, she took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat. Notice, Adam was "with her" so he knew what was happening. Adam should have stopped Eve but obviously did not. Notice verse 9, it was Adam the Lord called to account. And although much is made of Eve's punishment in childbearing it was actually Adam who bore the brunt of the judgement. 3:17 "And unto Adam he said, Because thou hast hearkened unto the voice of thy wife, and hast eaten of the tree, of which I commanded thee, saying, Thou shalt not eat of it: cursed is the ground for thy sake; in sorrow shalt thou eat of it all the days of thy life; 18 Thorns also and thistles shall it bring forth to thee; and thou shalt eat the herb of the field; 19 In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art , and unto dust shalt thou return." And Adam lived and suffered over 900 years before that sentence was completed.
(1) Genesis 1:29, 30 And God said, Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat. 30 And to every beast of the earth, and to every fowl of the air, and to every thing that creepeth upon the earth, wherein there is life, I have given every green herb for meat: and it was so.
(2) The King James version says "cherubims" which, while bad grammar and translation conveys to those without knowledge of Hebrew the true sense.