In Genesis 2:16 – 17 God told Adam and Eve they were free to eat from any tree in the garden, with the only exception being the tree of the knowledge of good and evil. There is no mention of them being forbidden from eating from the tree of life although both were in the center of the garden. For all we know they did eat from the tree of life.
God told them both that if they ate from the tree of the knowledge of good and evil they would die. This is the first mention of death as a consequence of sin.
After the encounter with the “serpent”, Adam and Eve sinned by doing what God expressly forbade them to do.
They had committed the first [original] sin(s).
Psalm 51:5 states: “Surely I was sinful at birth, sinful from the time my mother conceived me”.
1 John 1:10 states: “If we claim we have not sinned, we make Him out to be a liar and His word is not in us”.
Would these apply to the disbelief of “original sin”? That’s something to be considered.
So by sinning, they reaped the consequences that God told them would happen. Hence, death was brought into the world. The ground was cursed, as were both Adam and Eve.
If they had not been forced to leave Eden, they could have lived forever by eating from the tree of life. Obviously, God knew what would happen if they were to eat from it and He also knew how He would provide eternal life for mankind. Our finite human reasoning cannot fathom exactly how He will choose to bestow eternal life. However He does it, we must be humble and very, very careful to not presume to know the mind of God.
Proverbs 3:18 states that wisdom is [a] tree of life to those who embrace her; those who lay hold of her will be blessed.
While it doesn’t seem to be a reference to THE tree of life, I’m not convinced it has no relation to it. Consider this, Adam and Eve left the garden of Eden with the knowledge of good and evil, but there is no mention of them leaving with wisdom.
The sin of idolatry (putting their desires above God) and rebellion (by not obeying what He said) were the original sin(s).
So, the original sin(s) encompassed lust of the eyes (the fruit was pleasing to the eye), lust of the flesh (it was good for food) and the pride of life (wanting to be like God by knowing good from evil).
This is the account of the “Original Sin(s)”