1 Timothy 4:1 Now the Spirit explicitly says that in later times some will depart from the faith, paying attention to deceitful spirits and the teachings of demons, 2 through the hypocrisy of liars whose consciences are seared.
One of the reasons I am always begging Christians to read their Bible more, not just the parts that some mere human tells you to read, but the parts that God told you to read (The entire Bible) is there are many people who call themselves Christians, some of these even call themselves pastors that are preaching things that go against God’s word.
Even the best preachers are just mere humans, and humans can make mistakes. If you are only reading the passages that your preacher reads, you are apt to fall into the same errors that he has.
Acts 17:11 (KJV) 11 These were more noble than those in Thessalonica, in that they received the word with all readiness of mind, and searched the scriptures daily, whether those things were so.