Doctrine is “a set of ideas or beliefs that are taught or believed to be true.” Biblical doctrine refers to teachings that align with the revealed Word of God, the Bible. False doctrine is any idea that adds to, takes away from, contradicts, or nullifies the doctrine given in God’s Word. For example, any teaching about Jesus that denies His virgin birth is a false doctrine, because it contradicts the clear teaching of Scripture (Matthew 1:18). Revelations 22:18 states: “I warn everyone who hears the words of the prophecy of this scroll: If anyone adds anything to them, God will add to that person the plagues described in this scroll.”
https://www.gotquestions.org/Revelation-22-18-19.html
In many places, Scripture warns us against false doctrine. One such place is 1 Timothy 4:1: “The Spirit explicitly says that in later times some will fall away from the faith, paying attention to deceitful spirits and doctrines of demons” (NASB). The KJV words it as “seducing spirits, and doctrines of demons.” A doctrine is a teaching or a set of principles. The “doctrines of demons,” then, are things that demons teach.
There can be good and bad doctrines. The word doctrine can refer to the biblical teachings of a church or a pastor. Or, in the case of 1 Timothy 4:1, the ungodly teachings of Satan. Those who follow the doctrines of demons “will fall away from the faith.” That is, heeding the doctrine of demons is a serious matter because it involves a departure from the truth of Christ’s gospel.
How are the doctrines of demons promulgated? They are delivered through human instructors: “Such teachings come through hypocritical liars, whose consciences have been seared as with a hot iron” (1 Timothy 4:2). These false teachers are hypocritical; that is, their lives do not evidence the holiness they seemingly espouse. They are liars; that is, they deal in falsehood and knowingly lead others into apostasy. And they are beyond the reach of conscience; that is, they have found a way, in their own minds, to justify their lies. These false teachers may be personable, charming, and persuasive, but they do not receive their message from the Holy Spirit; rather, they spout the suggestions of evil spirits, whose work it is to lead people astray.
What exactly are the doctrines of demons? The immediate context gives an idea of the teachings to look out for: “They forbid people to marry and order them to abstain from certain foods, which God created to be received with thanksgiving by those who believe and who know the truth. For everything God created is good, and nothing is to be rejected if it is received with thanksgiving, because it is consecrated by the word of God and prayer” (1 Timothy 4:2–5). According to this passage, we should not follow any person or group that forbids marriage or that places restrictions on certain foods. Any person or group that says holiness comes through a select diet or complete sexual abstinence is lying.
In the Garden of Eden, Eve encountered the doctrines of demons as the serpent spoke to her: “He said to the woman, ‘Did God really say, “You must not eat from any tree in the garden”?’” (Genesis 3:1). At the beginning of the conversation, Satan questioned the teaching of God, and, as they continued to talk, he substituted his own teaching for God’s. Satan has continued to use deception, doubt, and subtlety to lead people astray. Satan is the father of lies and a murderer from the beginning (John 8:44), and the doctrines taught by his demons through the agency of willing human accomplices continue to separate people from God and His blessing.
Satan knows how to manipulate us, and that is why the doctrines of demons are so effective. We can identify the doctrines of demons by immersing ourselves in the truth. We must read and study our Bibles. When we know what God says on any given subject, then any deviation from that teaching will send up a red flag. When we are in tune with God’s Word, aberrations from that keynote will ring hollow and off-key.