2 Corinthians 12 tells us exactly why we must endure insults as we take our stand for the Gospel of Jesus Christ.
Paul did not boast of his own visions and supernatural events. He said that if he were to boast, it would be of the great things of others -- not of his own. When he boasted about himself, it would be towards his weaknesses, not his greatness.
Paul said that were he to boast of his own spiritual events, he would not be a fool; he was speaking the Truth. Nevertheless, he refrained from it so that no one would never elevate himself to a stature above that of the man he was.
Because of this, God allowed what Paul called a "thorn in the flesh." God allowed a messenger of Satan to harass him, for the sole purpose of keeping Paul from becoming conceited. Paul was not immune to the insults, and went through some of the same experiences that we go through in our walk with Christ. These insults were from a messenger of Satan through an insulting man of his day, yet God permitted it.
Three times Paul pleaded with God about this. He asked the messenger of Satan to leave. God's reply? "My Grace is sufficient for you, for My Power is made perfect in weakness."
Paul did not hide his weakness, he bragged about it. He said that he would boast it gladly, because in his weakness the power of Christ rested upon Paul.
He said: "For the sake of Christ, then, I am content with weaknesses, insults, hardships, persecutions, and calamities. For when I am weak, then I am strong."
As Christians, we should ask ourselves: Have we overcome to the point that we can brag about our weaknesses? Do we boast in pride of the spiritual events in our lives, or do we point this boasting to others? Do we boast of our own powerful experiences, or our weaknesses? Do we follow after men who boast of their own power? Do we harass and insult other children of God when Paul says that these insults are the "messenger of Satan?"