Skandelon
This is probably where I differ from everyone here, I do not see a fall in scripture. Man was created good, he was sinless and pure. But at the same time he was created flesh, and the flesh has desires and lusts. It was not just the serpent's lie that caused Eve to sin, it was also her natural desires. Satan appealed to these desires, he always goes for our weakness.
Gen 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.
It is easy to see here that this fruit appealed to Eve's flesh. It looked good for food, so it appealed to the appetite. It was beautiful and appealed to the eyes, it was desired to make one wise and so appealed to the mind and vanity.
And there is not one word about God cursing man's moral nature in the curse he pronounced after they sinned. So how did they change?
The change is they became sinners legally, and the death sentence was imposed upon them. I believe this especially to apply to spiritual death. They were immediately separated from God and hid from him when they heard his voice.
There was also a change in consciousness. Before they were naked and were and not ashamed, much like a small child. They had no conception of right and wrong, and had not before felt guilt.
But there is nothing in the scriptures that says they suddenly were overwhelmed with the compulsion to do evil. It also shows they were able to respond to God when he called them, so I do not see any inability to obey God here.
And Cain had the ability to do either good or evil.
Gen 4:6 And the LORD said unto Cain, Why art thou wroth? and why is thy countenance fallen?
7 If thou doest well, shalt thou not be accepted? and if thou doest not well, sin lieth at the door. And unto thee shall be his desire, and thou shalt rule over him.
The word "if" shown twice here shows that Cain had the ability to chose to do either good or evil. And further, God says Cain would rule over sin, so this teaching that man is utterly enslaved to sin is not scriptural.
Man was created flesh, and is still flesh, we see this theme throughout scripture.
Matt 26:41 Watch and pray, that ye enter not into temptation: the spirit indeed is willing, but the flesh is weak.
So, maybe I am wrong, but I do not see this "fall" everyone talks about. I was taught that and believed it myself for years, but when I studied the subject I could not find it in scripture. If anyone has scripture to show that man's moral nature was changed when Adam and Eve sinned, I will be glad to look at it.