The LORD God took the man and put him in the Garden of Eden to work it and take care of it. 16 And the LORD God commanded the man, "You are free to eat from any tree in the garden; 17 but you must not eat from the tree of the knowledge of good and evil, for when you eat of it you will surely die."

-Sin may be defined as the personal act of turning away from god and his will.
The bark/tree parts on adam represents is the process of death, the tree of life is leaving him and hes turning into sinful flesh,mind and soul.
The snake represents the serpant (the accuser)
The apple represents the fruit adam indulged in which brought death.

-Painted in PS CS