What is sin according to Bible?

A simple question we need answered is the identification of what sin actually is. The Bible gives us several brief descriptions of what constitutes sin.

"All wrong doing is sin." 1 John 5: 17
"Everything that does not come from faith is sin." Romans 14: 23
"Anyone, then, who knows the good he ought to do and doesn't do it, sins." James 4: 17
"Everyone who sins breaks the law; in fact, sin is lawlessness," 1 John 3: 4
It is an interesting point, that with these definitions of sin, not one refers to a devil or Satan. The writer James describes the sin process in detail, and yet leaves out any reference to a devil or Satan having any input to the process:
"Blessed is the man who perseveres under trial, because when he has stood the test, he will receive the crown of life that God has promised to those who love him. "When tempted, no one should say, 'God is tempting me.' For God cannot be tempted by evil, nor does he tempt anyone; but each one is tempted when, by his own evil desire, he is dragged away and enticed. Then, after desire has conceived, it gives birth to sin; and sin, when it is full grown, gives birth to death." James 1: 12–15

James here presents a logical process that begins with one's own evil desire, and finishes up with one's death. If there was a devil to blame, then certainly James did not mention it, although he had opportunity to mention it when he rejected all possibility of the original temptation step as coming from God.

The apostle Paul spoke of a similar situation from his experience. Note carefully his argument.
"For what I do is not the good I want to do; no, the evil I do not want to do - this I keep on doing. Now if I do what I do not want to do, it is no longer I who do it, but it is sin living in me that does it." Romans 7: 19, 20
Paul, in effect, states that there is something in the make-up of his flesh, that makes him sin. He refers to it as a 'sinful nature'. In the previous chapter, Paul had stated:
"Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all men, because all have sinned - for before the law was given, sin was in the world." Romans 5: 12, 13

It is clear from this passage, that Paul states that sin entered the world through one man, Adam. He does not say that sin entered the world through the devil or through Satan. In fact, throughout his letter to the Romans (in which he forcibly argues the nature of sin and its end result) he mentions 'sin' or 'sins' 48 times, but makes absolutely no mention at all of Satan, or of any devil. It would be well to reflect on this factor as we consider the subject of sin. The principal book of the Bible that deals with the subject of temptation and sin, Romans, does not mention the devil or Satan within its pages.