In Matthew 16:5-12, Jesus tells His apostles to beware of the leaven of the Pharisees and Sadducees. They do not immediately understand what He means, and Jesus chastises them for not understanding. It seems so obvious, but Jesus has to tell them what He means. And once He does, they understand that He means they are to beware of their teaching. The Pharisees and Sadducees were the religious leaders of the day. What would Jesus tell us today? Would He warn us to beware the leaven, doctrine, of the religious leaders of today? Of course He would because there exists false teaching. Even the religious leaders of today may be teaching doctrines of men that have spread throughout what is called “Christianity” today. For us to be aware of the leaven, we must “test the spirits,” 1 John 4:1. The fact that someone is teaching falsely will not be miraculously put into your brain, it will not be spoken by a prophet to you, it will not be given to you as some sort of leading feeling. It will be determined by you as you weigh it against what God has already given to you in His word. In other words, it is your responsibility. Just as Jesus made it the responsibility of the apostles. Never let someone tell you something is true without searching the scriptures as the noble-minded Bereans did, Acts 17:10-11.