One reader ("Orthodox") asked:
So why did Adam sin? Because God made him bad?
Adam ate the forbidden fruit because he listened to his wife, rather than God.
Genesis 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;
Adam did not take it because he was deceived by the serpent (though the woman was deceived by the serpent):
1 Timothy 2:14 And Adam was not deceived, but the woman being deceived was in the transgression.
Adam explained his own action this way:
Genesis 3:12 And the man said, The woman whom thou gavest to be with me, she gave me of the tree, and I did eat.
So, in the end, what is the easiest answer we can give?
Adam loved the gift more than the giver. He loved his wife more than he loved God.
Adam was placed in a situation in which he was tempted to sin, and Adam did not resist the temptation.
God made Adam good, but God also made Adam fallible. At the appointed time, Adam fell - and in him all those whom he represented: his wife and all his natural descendents.
Then, in the fullness of time, God sent His only-begotten Son, the Lord Jesus Christ to be the second Adam. All those who obtain life from Adam, die with Adam, but those who die with Christ from him receive life everlasting.
Praise be to God!
P.S. As an aside, it's worth noting that philosophically we understand Adam as having a free will that was not bound by a corrupt nature. That is to say, while Adam might have had certain external constraints, he had different internal contraints than Cain, Abel, and Seth had. His will was not a slave to sin until he fell. Adam before the fall is not similar to us before grace. We are born in bondage to sin, slaves to sin. We are born not as the sons of God, but as enemies of God. It is only by the exceeding mercy of God that any of us are saved.