The apostle Paul wrote one of his strongest defenses of the gospel against those who were teaching that they had to keep the Law and become Jewish to be saved. That's when he wrote the book of Galatians. He wrote in the introduction that he was astonished at the Christians in Galatia, because they were so soon being turned from God's message of grace to a different gospel. He said, "not that there is another one, but there are some who trouble you and want to distort the gospel of Christ. But even if we or an angel from heaven should preach to you a gospel contrary to the one we preached to you, let him be accursed. As we have said before, so now I say again: If anyone is preaching to you a gospel contrary to the one you received, let him be accursed." (Galatians 1:6-9)
This was perhaps the strongest condemnation Paul ever pronounced against anyone, and the reason he did so was because those false teachers had distorted the gospel so badly that they were teaching a different way of salvation than the way God had announced through Jesus to the apostles--which was complete salvation by grace alone apart from any good works that we could perform (Luke 18:9-17; Ephesians 2:1-10). So Paul was very upset because they were actually changing the message of salvation. And that is why we have the practice of apologetics today in the Church. As Jude 1:3 says, "Beloved, although I was very eager to write to you about our common salvation, I found it necessary to write appealing to you to contend for the faith that was once for all delivered to the saints." Jude also saw how it was necessary to contend for the faith and defend it against distortions, even though he would have rather written to them about something else.
Because of all this, we ought to watch out that people don’t influence us in the wrong ways. For example, the early Christians believed what Jesus taught about having the freedom to eat any kind of food as long as we give thanks to God for it. They also warned against the popular teaching of that time that said we must avoid eating certain things in order to be holy or pleasing to God. In 1 Timothy 4:1-5 Paul wrote: "Now the Spirit expressly says that in later times some will depart from the faith by devoting themselves to deceitful spirits and teachings of demons, through the insincerity of liars whose consciences are seared, who forbid marriage and require abstinence from foods that God created to be received with thanksgiving by those who believe and know the truth. For everything created by God is good, and nothing is to be rejected if it is received with thanksgiving, for it is made holy by the word of God and prayer."
Notice how Paul wrote that "the Spirit expressly” said these things. This means God really wanted us to know that in the last days people would start leaving the truth for other beliefs. Paul even said that false beliefs are from "the teachings of demons." One of those teachings was that people would forbid marriage. Another teaching was that they would require people not to eat certain foods, and he adds, "that God created to be received with thanksgiving by those who believe and know the truth." Obviously God knew these things would become a problem and so He warned us ahead of time in the Bible to protect us from error.
Another area that the New Testament makes really clear is our need to discern the difference between true and false teachers. Jesus warned that many false teachers would come in His name, but that we should not follow them. While they usually look good on the outside as “wolves in sheep’s clothing,” nevertheless there is a way to recognize them. The way Jesus taught us to tell the difference was by their message and their lifestyle. Hesaid you can judge a tree by its fruits. A good tree makes good fruit but a bad tree produces bad fruit. (Matthew chapter 7)
We don't have to be extremely educated or know a whole lot about everything to tell the difference between good and bad fruit. We just have to know what it is. As Christians, it is important that we learn as much as we can about what God's Word teaches, so that we will become better able to rightly judge between the good and the bad (Hebrews 5:12-14). A simple way to do that is to just know the gospel really well and know who Jesus is according to the Bible. The Bible shows that most deception involves a distortion of who Jesus is and what the message of the true gospel is. Since the it teaches that Jesus is God in human flesh (John 1:14), then most cults and false religions in the world today usually deny some aspect of His God-Man nature. Oneness Pentacostals, such as T. D. Jakes and others, deny the doctrine of the Trinity, which can be seen on almost every page of Scripture. The reason it is so important is because the letter of 1 John makes our belief about who Jesus is one of the tests of true faith. ohn also wrote in John 1:1 that He was both “with God” and “was God” (in His nature) at the same time, but that He is not the same as the Father or Spirit (John 16:13; 17:5). Some people don’t like the doctrine of the Trinity because it is hard to understand, but that shouldn’t discourage us from believing what He revealed about Himself in the Bible.
The other problem that comes up is the message of the gospel. It is solely by God's grace and goodness, and because of His own free will and love, that we are saved by faith in Jesus. We are made new in Christ, so that we live for Him and His eternal Kingdom now. But this simple message is often distorted when people say that we must do good works in order to be saved, such as circumcision (in the early church), or baptism, or the Lord's Supper, or obedience to the Law. All of those things are good and necessary when properly used. The Old Testament sign of the covenant was circumcision, and Jesus commanded baptism and the Lord's Supper, and also taught us to obey God's law (Matt 5:17-19). But none of those can make it possible for us to go to heaven, because that is a free gift. Yet that is precisely what many false teachers denied back then and still deny today. I used to go to a church in Pittsburgh that denied salvation by grace through faith alone. I felt terrible that I fell for that, because that’s what Paul was warning about in Galatians, as well as his other letters.
James chapter 2 also warns us about those who say they have faith, but who do not have good works to back it up. He taught that our faith is rather proven to be genuine by our life of humble obedience, love for others, and good works, though they do not earn our salvation. There are other ways the truth is denied by false teachers, but these are some of the most important ways the Bible warns us about.
Peter and Jude, as well as John (known as “the apostle of love”), wrote specifically to help us tell good teachers from bad ones. Peter said that the "ignorant and unstable" distort the Scriptures (2 Peter 3:14-18). Jude said they pervert the grace of God into immorality and deny Jesus (Jude v.4). He later said, “Yet in like manner these people also, relying on their dreams, defile the flesh, reject authority, and blaspheme the glorious ones” (v.8). The glorious ones refers to angels, but is in the context of how such people aren’t afraid to speak blasphemously of authoritative powers. Jude may have had Exodus 22:8 in mind, which says, “"You shall not revile God, nor curse a ruler of your people.” Jude then said that even the angel Gabriel would not say anything slanderous of an authority, not even to the devil himself, but instead appealed to God as the Judge. That was because all authority is given by God. Even though many authorities might not be just or act rightly, they are still to be spoken of respectfully in fear of God. But false teachers usually reject the authority of good Christian pastors and teachers, and they speak badly of them, and often set themselves up as their own authority. They don’t like to do what God's Word says about humble submission to other faithful believers in obedience to Christ. Jude warned us about people like that so that we wouldn’t follow their example.
Most of the New Testament was written in response to these very problems. And thank God He gave us all this information ahead of time, so that we know exactly how we can please Him and bring glory to His name by an assured faith! It is so wonderful that we know these things, because the more we stand firm in the truth delivered to us, the harder it will be to distract us from glorifying the Lord Jesus by our lives, and God will be praised!
Some people are easily led astray by conspiracies, and we can all be affected by them if we are not careful. A verse that has been a good encouragement to me in confusing situations is Isaiah 8:11-13, “For the LORD spoke thus to me... and warned me not to walk in the way of this people, saying: ‘Do not call conspiracy all that this people calls conspiracy, and do not fear what they fear, nor be in dread. But the LORD of hosts, him you shall honor as holy. Let him be your fear, and let him be your dread.’” This is also a reason why I think it is just good for Christians to learn more about the Bible at a good church. Of course, no church is perfect, but neither are we. We are just glad to be in God’s grace and to learn with others who are standing firm, too!
So I wrote all this because I hope it will encourage you not to let many of the confusing things out there get you down. I also know of many other ways our hope in God and His Word can be hindered by Satan through false teachings, but I wanted to write to warn you of those things which can quickly make us forget how the Bible says we already have everything we need in Jesus Christ our Lord! (Colossians 1-2)