Where Temptation Comes From
Temptation is the desire to do something wrong or unwise. It is the thought which precedes sinful actions. This makes it a part of the process that leads to sin and hence to death. The Bible makes this explicit in the Letter of James:
"Let no one say when he is tempted, “I am being tempted by God,” for God cannot be tempted with evil, and he himself tempts no one. But each person is tempted when he is lured and enticed by his own desire. Then desire when it has conceived gives birth to sin, and sin when it is fully grown brings forth death." (James 1:13-15)
The process here is explicit; temptation comes from our desires, and can produce sin, which ultimately leads to death. The important point for this study is that the temptation to sin comes from our own minds. We have desires for things, and these desires lead us on to break the moral principle laid down for us by God, and hence to commit sin.
The First Letter of John describes the source in these terms:
"For all that is in the world—the desires of the flesh and the desires of the eyes and pride of life—is not from the Father but is from the world." (1 John 2:16)
The things that produce sin are described under three headings: the things we desire because they satisfy our bodily desires, the things that we desire because they look good, and the things that satisfy our pride. All these, of course, are internal things, things that come from our own human nature.
Jesus also confirms this picture:
"And he said, 'What comes out of a person is what defiles him. For from within, out of the heart of man, come evil thoughts, sexual immorality, theft, murder, adultery, coveting, wickedness, deceit, sensuality, envy, slander, pride, foolishness. All these evil things come from within, and they defile a person.'” (Mark 7:20-23)
This passage gives a broad picture of sins, from envy and pride to adultery and murder. The point of them is that they all come from our innermost thoughts, which is what the Bible means when it uses the phrase “the heart of man”.
The same phrase appears in Jeremiah’s prophecy:
"The heart is deceitful above all things, and desperately sick; who can understand it?" (Jeremiah 17:9)
The point here is that the human heart - our inmost thoughts - tends to lead us on to sin, and we tend to be deceived by it.
The important lesson to learn is that the things that lead us away from God will be our own internal desires, thoughts and intentions.