Jesus seems to be saying to Peter, mind your own business. Your duty is to follow me, not to be overly concerned about what others are doing. That is good advice for us in today’s world as well. We need to stay focused on Jesus and not those around us. Yes, we need to respect those that are in spiritual authority over us, but we are not to make them idols. Sooner or later, the flesh will fail, but Jesus never has failed and He never will fail. What we need to do is accept Jesus as Lord of our life, obey His commands, follow His example and do what He has called and gifted us to do in His Kingdom. If we stay faithful in doing that, we will little, if any, time to criticize and judge our brothers and sisters. Doing this means we cannot and do not accept blindly the words of others. We must make sure they are aligned with the Holy Scriptures.
20 Do not scoff at prophecies, 21 but test everything that is said. Hold on to what is good. 22 Stay away from every kind of evil.–1 Thess. 5:20-22 (NLT)
As Pres. Ronald Reagan said: Trust but Verify!