Despite the charge of unfairness that Adam ruined things for everyone else, it could well be that God knew that any of us human beings would have freely disobeyed in the garden. Many have wondered, “Why should Adam be our representative head? He fouled things up for everyone else, and now we’re paying for it.” An unarticulated—perhaps even arrogant— presumption stands behind this complaint: “If I had been in Adam’s place, I would have obeyed God’s simple command not to take fruit from the tree. I could have prevented the disastrous fallout from the first disobedience.” However, what if every human being God created would also have committed the primal sin, just as Adam did? Had any of us been in Adam’s place, perhaps we would have—without exception—freely chosen to disobey. While human sinlessness is theoretically possible, God knew that any created human being still would have freely chosen the same course, resulting in the same curse. Selecting another person would have produced no different outcome.
This last point doesn’t address the questions of the exact connection between Adam and the rest of the human race and how corruption is transmitted. It does, however, relate to the inappropriateness of blaming Adam, whether expressly or implicitly: God, I thank you that I am not like Adam. This deflates the charge of divine injustice since God knows the rest of us would have freely acted in the very same Adamic way in the same circumstance.
— Paul Copan, from Loving Wisdom, kindle location 2071