Doctrine, as many would define it, is not popular in religion today. Many believe that doctrine is what divides us. The denominations mostly leave matters of “doctrine” to the heads of their denomination. The preachers/pastors then can limit their message to topics like salvation, grace, love, social issues, etc. In the Lord’s church, some are de-emphasizing “doctrine” so they can focus more on the “gospel” (a faulty distinction that is not made in the New Testament). But doctrine simply means teaching. Many passages in the King James Version that use the word “doctrine” actually have the word “teaching” used instead in some of the newer translations. There is no complicated definition of “doctrine.” That which is taught in the New Testament is doctrine.

The intent of this article is to show the importance of doctrinal purity. In the previous paragraph we noticed what doctrine is — the teachings of the New Testament. Purity means it is unchanged, uncorrupted, and complete. So when I speak of the need for doctrinal purity, I am referring to the desire to learn and believe all that is taught in the New Testament, and only that which is taught in the New Testament. Many find this undesirable or impossible. But the word of God teaches that this is what we must strive for.

Does It Matter What We Believe?

Many believe that it does not matter what we believe. Most people in the religious world believe that each one can have his own interpretation or opinion. If we disagree, neither one can say the other is wrong, because each one’s idea is valid. But this popular idea is not taught in God’s word. Paul told the Ephesians that when they read his writings, they could “understand” his “insight” (Eph. 3:4). Not that they would have their understanding and he would have his. They could have the same understanding because God designed His word to be understood, and He is not “the author of confusion” (1 Cor. 14:33).

The Bible teaches that there is one truth, not a multitude of truths equal to the number of people living on the earth. Jesus said, “I am the way, and the truth, and the life” (Jn. 14:6). He told Pilate that He came “to testify to the truth” (Jn. 18:37). Paul tells us that we must love and believe the truth if we wan to be saved (2 Th. 2:10,12).

This leads to the question: can we be right without believing right? Can we be “off” on an issue that is a matter of belief, but not a matter of practice? This question often results in brethren attempting the treacherous task of determining which issues are matters of salvation and which are not. Before we get carried away in dividing issues into salvation and non-salvation categories, let’s look to the New Testament and see if we can get an idea of how important it is that we believe what is right.

New Testament Examples

There are a couple examples we can consider. The first is in 2 John 7-11. “For many deceivers have gone out into the world, those who do not acknowledge Jesus Christ as coming in the flesh. This is the deceiver and the antichrist. Watch yourselves, that you do not lose what we have accomplished, but that you may receive a full reward. Anyone who goes too far and does not abide in the teaching of Christ, does not have God; the one who abides in the teaching, he has both the Father and the Son. If anyone comes to you and does not bring this teaching, do not receive him into your house, and do not give him a greeting; for the one who gives him a greeting participates in his evil deeds.”

In this passage, John is dealing with the beginnings of Gnosticism. The Gnostics denied that Jesus came in the flesh. Why? They believed that all flesh/matter was evil. Therefore, since Jesus is God (and therefore, perfect), He could not possibly have come in the flesh. These people were off on a point of doctrine. Yet they were called deceivers, antichrists, and said to be out of fellowship with God. Would it be alright for the Christians there to believe this about Jesus? No! The Holy Spirit thought it was incredibly important that the Christians there did not believe this teaching. That is why there is the warning to not receive this false teacher into one’s house or even give him a greeting.

In 1 Corinthians 15, Paul addressed the topic of the resurrection. Some among them were teaching that “there is no resurrection of the dead” (1 Cor. 15:12). Why would Paul spend the rest of the chapter explaining the truth on this issue if it didn’t matter what one believed? He actually told them that if it were true that there was no resurrection, then Christ was not even raised (v. 13), the apostles were false witnesses (v. 15), their faith was worthless (v. 14,17), they were still in their sins (v. 17) and were of all men the most to be pitied (v. 19). He told Timothy that a similar belief, that the resurrection had past, had overthrown the faith of some (2 Tim. 2:18).

Paul warned the Corinthians, “Do not be deceived: ‘Bad company corrupts good morals’” (1 Cor. 15:33). We typically hear this verse used as a warning for Christians not to closely associate with those who drink alcohol, smoke, use bad language, etc. The principle here certainly applies. But this warning comes right in the midst of Paul discussion about the resurrection. In this context, Paul is warning against having a close association with those who could cause us to believe error. Paul believed it was important that these brethren believed the truth and were not led to believe something that was false.

Erroneous Views Can Potentially Lead to Sin

One of the dangers of error is the potential for it to cause one to sin. The first example we noticed from Scripture was the denial that Jesus came in the flesh. This was based on the Gnostic idea that all matter was evil. Over time, the Gnostics came to believe that the spirit was good and all flesh was evil. Therefore, they believed they could sin in the flesh, since the flesh was evil anyway, but their spirit was kept pure. This opened the door to fornication, lasciviousness, and other sins.

In the case of some denying the resurrection, the acceptance of this belief could also eventually lead to sin. People could start to wonder what the point was in living righteously if there was no future judgment with the promise of either a reward or punishment. “If the dead are not raised, let us eat and drink, for tomorrow we die” (1 Cor. 15:32). People would believe there was no accountability. Therefore, they could do as they wished. This is one of the dangers of error — it opens the door to sin.

What if an Erroneous View doesn’t Lead One to Sin?

Some do not like the “slippery slope” line of reasoning that says that one thing is wrong because it could lead to something else. This reasoning certainly does have its limitations. We cannot forbid others of a liberty because it might lead to sin later. But we really don’t have to use the “slippery slope” argument here. Is it possible for one to hold an erroneous view (such as believing that Jesus did not come in the flesh or that there is no future resurrection), yet never sin because of it? Sure, it’s possible. But that does not mean they should adopt or continue to hold that erroneous view. The Holy Spirit, through the writings of Paul and John, took great pains to tell Christians not to believe what was false.

Really, it all comes down to a matter of faith. Do we love the truth and desire to believe the truth. Paul says we must if we want to be saved (2 Th. 2:10,12). So yes, it does matter what we believe. Our salvation depends on us loving and believing the truth. Who are we to say that it doesn’t matter what one believes, as long as no sin is committed? God does not want us to believe just anything, He wants us to believe the truth that He has revealed in His word. It is a matter of faith because “faith comes from hearing, and hearing by the word of Christ” (Rom. 10:17).

Application for Today

Denying the resurrection or Jesus coming in the flesh is not common among Christians today. But what about other issues? Can one believe the days of Genesis 1 are figurative when the Bible clearly teaches that they are literal, consecutive, 24-hour days (Gen. 1:5; Ex. 20:11; Mk. 10:6)? Is it alright if one believes the flood was just a regional flood when God’s word tells us it was a global flood (Gen. 7:19-20; 2 Pet. 3:5-6)? Can one deny the deity of Christ, when the New Testament affirms that Jesus was, is, and forever will be Deity (Mt. 16:18; Jn. 8:24; Col. 2:9)?

Whatever the word of God says, we must believe it. If we want to be people of faith, we must love and believe the truth. Let us never think that believing something that is false is no big deal. We must continue to study the word of God, learning, believing, and accepting its teachings, so that we will be accepted by Him.