The Lord Jesus was teaching some things “openly” with which Peter was not comfortable (namely, about His suffering, rejection, death and resurrection), and so “Peter took Him aside and began to rebuke Him” (Mark 8:31-32). Can you imagine? Rebuking the Lord because of what He was teaching publicly?
“But when [Jesus] had turned around and looked at His disciples” (no doubt to consider what they needed and the truths they needed to understand), “He rebuked Peter” (8:33). Peter’s actions were not acceptable! Jesus told him, “Get behind Me, Satan! For you are not mindful of the things of God, but the things of men” (8:33). Peter THOUGHT that he was being mindful of the things of God, but Jesus told him it was just the opposite.
Is it possible that you or I might not be comfortable with some of the truths of Jesus? Are we especially uncomfortable if they are taught “openly”? If that is the case, the message of Jesus to us is that we are “not mindful of the things of God, but the things of men.” Think about it.