The First Adam, The Last Adam (and all the rest of us)

Adam and Eve

Adam and Eve were created in the image of God on the 6th day of creation. They were created as adults with all their intellectual capacities intact. They were also created as independent moral agents who'd remain in a state of innocence, so long as they didn't disobey God.

The first command given them (which was given to all creation) was to "be fruitful and multiply". This command was likely engaged in fairly soon after being created. We know no children were born before the fall, but if one was conceived before the fall; we are never told, but that is a possibility.

The second command given to them, was to keep and care for the garden. (Genesis 2:15) Entailed in this command, they were to protect the garden from invaders; but since there was no direct instruction as to what to do, it was left to their discretion to make that decision. So as soon as the serpent showed up; at the very least they should have notified God.

The third command - which since they didn't obey the second one; is the one that "got them". This was not to eat of the tree of the knowledge of good and evil. (Well we all know what happened there!)

Mode of Revelation:

Adam and Eve had direct access to God. Anything they wanted to know; all they had to do was ask. There was no written Scripture at that time, so any revelation they received was of direct communication. It seems likely too that both had equal access to God, because the declaration that Eve's "desire would be toward her husband and he shall rule over her" didn't come until after the fall.

Now Adam and Eve were still capable of doing something that offended God, they were just not aware of this until they'd been given commands. Yet if given a command because they'd displeased God, so long as they obeyed, they remained in a state of innocence.

Even if they hadn't eaten the fruit of the forbidden tree, eventually they would have been given a command they would have disobeyed. Their disobedience was inevitable and predictable. God knew this (because He's omniscient) and had made plans to compensate for this reality before creation was ever commenced.

Even so, they'd both been given a "free will"; meaning their ability to make decisions wasn't encumbered by knowledge of sin, or a corrupted nature that came about as a result of willful disobedience. 

Eve was the first one to eat the fruit, yet note that they were not made aware of their disobedience, nor were they expelled from the garden until Adam ate the fruit. Later on, 1 Timothy 2:14 explains that Eve was deceived, but Adam was not. Even though she'd done something she knew she wasn't suppose to; that was still not considered "willful disobedience" because she was deceived.

Consequence of knowledge of good and evil:

Now if she alone, or she with Adam had gone to God and said: "I screwed up." They probably would have received further instruction as to how they'd failed in protecting their garden and so long as they continued to obey; they would have remained there. 

Now would she have been considered "corrupted" at that point is a good question.

Either way, the lesson this presented to both Adam and Eve was that they were fallible. They could not "be God" even in possessing the knowledge of good and evil because they as created creatures, were fundamentally different in nature than God. They weren't omniscient, omnipotent, omnipresent or eternal and gaining the knowledge of good and evil would not have made them so. Now the stipulation that they would be "like God knowing both good and evil" was technically true; but knowledge of good and evil does not give you these other 4 attributes of God's Being.

Now apparently Adam knew this. Did Eve? Ironically, the text in Genesis says Eve desired the fruit because she wanted to be wise. (Wise like unto God; not realizing this knowledge would corrupt her on account of the fact that her nature was fundamentally different than God's.) And this is where she was deceived because she may not have intended that the obtaining of that knowledge was to make her omniscient, omnipotent, omnipresent or eternal. 

She wanted God's wisdom, not necessarily His attributes; but this tree was not the "tree of the wisdom of good and evil" it was the "tree of the knowledge of good and evil". And here is how she was truly deceived because wisdom (Godly wisdom) is derived from these other attributes of God, not simply from the knowledge of good and evil.

Could Adam and Eve obtain knowledge of good and evil without it corrupting them?

No they couldn't. And the reason for this is because they were not instilled with a Divine nature. And being instilled with a Divine nature is what made Jesus fundamentally different than Adam.

Now because having been the first humans created, Adam and Eve could not have been instilled with a Divine nature because life had to exist before a Redeemer could be incarnated. And since the command to "be fruitful and multiply" had predated the eating the fruit of the tree of the knowledge of good and evil; the incarnation did not take place on the front end of creation's time table.

Theoretically, it could have. God would had to have reversed the instructions given to Adam and Eve and the Redeemer would have had to have been born before Adam and Eve's relationship was consummated. 

Also, theoretically, God could have chosen any of Eve's daughters at any point in the unfolding of time. God though chose and planned on waiting until a considerable amount of time had transpired for the intent of bringing revelation to humanity about our state as fallen creatures, our need for redemption, and how this was going to unfold.