Like the Messiah, we must deny ourselves.
Put Satan into this picture. What is he going to do to us? Through disinformation and affecting our attitudes, he will lead us toward self-satisfaction, not self-denial, because self-satisfaction is the essence of sin. When we sin, we bring upon ourselves the death penalty.
To teach the right lesson, Jesus immediately taught—to counteract what Satan was subtly teaching through Peter—that the way to the Kingdom of God is through self-denial, not self-satisfaction. Satan will try to persuade us not to deny ourselves but to fulfill ourselves at the expense of others.
Another thing this can teach us is that great temptations can come through well-meaning friends. Peter meant well. It must have shocked him right out of his sandals when Jesus turned and said, "Get behind Me, Satan!" right in Peter's face. Jesus was probably not angry, just urgent, so that Peter would grasp what had happened.
Surely, God would not want us to face this kind of a trial, would He? Yes, it could happen if the temptation comes through well-meaning people. We are particularly vulnerable when we can be led to believe that we are not being treated as we deserve.
Satan used this major ploy against Adam and Eve: "Oh, has God said so? He's withholding from you." Such was his implication. "Why, if you do things the way you want, you can have much more. You can be god." We always want more; it is part of human nature.
Unfortunately, mankind keeps making things worse by making the same general mistakes over and over again in each generation. It will not end until each individual decides he will not do it regardless of the cost to himself. This is denying oneself. Some things in life are beyond our control, and we must leave them to God to solve.