Called to Judge False Doctrine
Trinity 8| Matthew 7:15-23| Pastor James Preus| Trinity Lutheran Church| July 26, 2026
At the beginning of this chapter of Matthew, Jesus says, “Judge not, that you be not judged.” And so, it may seem surprising that just a handful of verses later Jesus then commands us to beware of false prophets, something that cannot be done without judging. But when Jesus teaches us not to judge, He is not forbidding anyone to judge under any circumstance, but rather, He is teaching us not to judge our neighbor where we have not been given authority to judge, but rather to defend him, speak well of him, and put the best construction on everything. But God has given every Christian the authority and the obligation to judge the preaching of their pastor and of every other preacher they may hear. St. Paul writes in 1 Corinthians 2, “The spiritual person judges all things, but is himself to be judged by no one.” (vs. 15) And St. John warns us, “Beloved, do not believe every spirit, but test the spirits to see whether they are from God, for many false prophets have gone out into the world.” (1 John 4:1)
And it is important that every Christian be diligent in this God-given-duty to judge preachers and their teaching, because Jesus warns that such false prophets will wear sheep’s clothing. What does it mean that false prophets wear sheep’s clothing? It means that they will disguise themselves as faithful preachers within the Christian Church, claiming to proclaim true, saving, doctrine. They will claim to speak God’s Word, to lead astray, if possible, even the elect (Matthew 24:24). St. Paul writes in Romans 10:
13 For “everyone who calls on the name of the Lord will be saved.”
14 How then will they call on Him in whom they have not believed? And how are they to believe in Him of whom they have never heard? And how are they to hear without someone preaching? 15 And how are they to preach unless they are sent? As it is written, “How beautiful are the feet of those who preach the good news!”
Yet, Scripture warns that there will be imposters disguising themselves as those who preach the good news. And since saving faith comes from hearing, and hearing through the word of Christ (vs. 17), it is imperative that we know whether we are hearing Christ’s word or the word of an imposter!
St. Paul instructs Titus on the qualification of a bishop, “He must hold firm to the trustworthy word as taught, so that he may be able to give instruction in sound doctrine and also to rebuke those who contradict it.” Sound doctrine is the pure, unpolluted teaching of Christ as it is found in Holy Scripture. The Bible is God’s Word. St. Paul writes about the Bible in 2 Timothy 3, “All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness” (vs. 16). And so, if you want to know whether you are hearing the voice of your Good Shepherd or the voice of a false prophet, you need to recognize what sound doctrine is from Holy Scripture. Yet, today most people do not think “sound doctrine” is important. “Just so long as we “love Jesus,” that’s all that matters. We should focus more on what we agree on rather than where we differ. This ‘beware of false prophets’ business is too combative and divisive. False doctrine can’t be that bad.”
But false doctrine is so bad for two reasons. First, because it dishonors God and breaks the Second Commandment. The Second Commandment is, “You shall not misuse the name of the Lord your God.” God’s name is misused in no worse way than when false things are taught in God’s name. Our Catechism teaches us about the first petition in the Lord’s Prayer, Hallowed be Thy name, “God’s name is kept holy when the Word of God is taught in its truth and purity, and we as the children of God also lead holy lives according to it. Help us to do this dear Father in heaven. But anyone who teaches or lives contrary to God’s Word profanes the name of God among us. Protect us from this, heavenly Father.”
Second, false doctrine is so bad, because it endangers our souls, leading us away from true saving faith in Christ Jesus. Many churches today have followed the course of the world and no longer call sin what the Bible calls sin. Some churches even put up flags celebrating pride in sexual perversion. They ignore what St. Paul writes in 1 Corinthians 6, “Or do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor men who practice homosexuality, nor thieves, nor the greedy, nor drunkards, nor revilers, nor swindlers will inherit the kingdom of God.” (vss. 9-10) These false prophets are loved by the world, because they seem so friendly and kind. But you cannot be more kind than Jesus, who says He has not come to call the righteous, but sinners to repentance. Scripture preaches the Law to us, so that we recognize our sin and our need for forgiveness. To continue in sin without repenting leads us to hell. So, these false prophets who say that fornication, homosexuality, and other sins forbidden by Scripture are not sins are like the fake friend who encourages the alcoholic to keep drinking or the drug addict to keep sticking the needle in his arm. Instead of helping them, by pointing to Christ who sets sinners free from slavery to sin and death, they only push them further into slavery and ultimately death and hell. Yet, the faithful preacher preaches the Ten Commandments and calls sinners to repentance, so that they may recognize their need for Christ and be saved.
Many churches today deny that Scripture is without error. They deny many of the miracles in Scripture. They say many of the stories didn’t really happen. This is especially true about the creation account, which many say could not have happened as Moses recorded it in Genesis. Rather, they say that life developed on earth over millions of years of evolution, because it is too fanciful to believe that God created full grown trees, birds, fish, and land animals with His Word and formed the first man Adam out of the dust and the first woman Eve from his rib. Yet, if we are going to reject the creation account because it is too fanciful, then will we also reject as non-historical Jesus’ resurrection from the dead? And if Jesus didn’t rise from the dead, on what do we base our own resurrection? If it is a myth that God formed Adam out of the dust, is it also a myth that God will raise us from the dust at the resurrection? If God could not create a world free from death, but needed to use millions of years of death and decay, how can we know that He can create a new heaven and a new earth free from death? And so, rejecting the historical accounts of Scripture does not leave untouched the comforting doctrine of Christ’s victory over death and the resurrection to eternal life.
The most damaging false teaching attacks the Gospel directly, claiming that we can be saved by our own works. Now for us Lutherans, this teaching sounds horrible. But the proponents of salvation by works make it sound very attractive. They say, “If we only seek God or at least try to do our best, then God will save us.” And so, many abandon faith in Christ, because they think they can be saved by trying to be a good person, which most people try to be. But that is not what Scripture says. Rather, Jesus says, “You must be perfect, as your heavenly Father is perfect.” (Matthew 5:48) And St. Paul writes, “For all have sinned and fall short of the glory of God.” (Romans 3:23) And so, those who teach that you can be saved by your work leave people either in false security, so that they do not trust in Jesus, or in despair, because they recognize their sin, but do not recognize that Christ comes to save sinners. And so, Christians should mark and avoid any church that teaches that you can be saved by your works or that denies that faith in Christ alone saves.
Now, there are many Christian churches that teach errors, but also teach a lot of truth. And in those churches, there are many Christians, who believe the Gospel of Christ and will be saved. And so, since these churches teach some true things and there are Christians within them, people conclude that it is not a big deal if they get some of the so-called minor things wrong. Yet, there is no safe amount of false doctrine. Rather, St. Paul warns in Romans 16, “I appeal to you, brothers, to watch out for those who cause divisions and create obstacles contrary to the doctrine that you have been taught; avoid them.” And so, we should mark and avoid all false teachers.
For example, Jesus commanded that all nations be baptized (Matthew 28:19). St. Peter writes that Baptism saves (1 Peter 3:21) and that the promise of Baptism is for children (Acts 2:38). Yet, many churches forbid the baptizing of babies, saying that Baptism does not save. Yet, the promise of Baptism, that it joins you to Christ’s death and resurrection (Romans 6), forgives sins, gives the Holy Spirit (Acts 2:38), and grants salvation to all who believe is then robbed of little children. Faith then is presented as our work instead of a gracious gift from God, given even to babies.
Jesus says in John 20, “If you forgive the sins of any, they are forgiven them. If you withhold forgiveness from any, it is withheld.” (vs. 23) Yet, many churches teach that the church cannot forgive sins, because only Jesus can forgive sins. So, they ignore the very words of Jesus, which state clearly that His ministers have the authority and command to forgive sins. And so, people are robbed of the certain comfort of the absolution. They cannot hear Jesus’ messenger tell them that their sins are forgiven.
Jesus said on the night in which He was betrayed, “Take, eat. This is My body given for you. Take, drink. This cup is the new testament in My blood, shed for you for the forgiveness of sins.” (Matthew 26:26-28; Mark 14:22-24; Luke 22:19-20; 1 Corinthians 11:23-25) Yet, because they think it is impossible, churches ignore these clear words of Jesus, and so they withhold the true body and blood of Christ, which grants forgiveness of sins, life, and salvation to all who believe. And so, you see that there is no safe amount of false doctrine, but all false doctrine is poison that seeks to deny you comfort from Christ Jesus. And you also see that Jesus commands us to beware of false prophets, because He loves us and wants to save us. He wants us to have full assurance of our salvation and every benefit from His suffering, death, and resurrection which He gives to us.
Jesus has called you to judge the preaching of pastors to see whether it is the Word of Christ or the word of a false prophet. But how can you be prepared to judge preaching? You are prepared to judge preaching when you have faith in Christ from Holy Scripture. Jesus says, “My sheep hear My voice. I know them and they follow Me.” (John 10:27) Yet, He says, “A stranger they will not follow, but they will flee from him, for they do not know the voice of strangers.” (vs. 5) Those who have faith in Christ, recognize His teaching. They know Jesus’ teaching from Holy Scripture. This is why we should not only pay attention to the reading of Scripture in church, but we should read our Bibles at home. We should especially pray our Small Catechism, which simply and briefly teaches the doctrine of Holy Scripture. When you recognize that the purpose of Holy Scripture is to direct you to Christ’s suffering and death for your sins and His glorious resurrection, so that you may have forgiveness and eternal life, and to direct you to where you can find that forgiveness in His Word and Sacraments, then you guard the teaching of Scripture and you recognize when someone is twisting it to lead you away from Christ.
Increase my faith, dear Savior,
For Satan seeks by night and day
To rob me of this treasure
And take my hope of bliss away.
But, Lord, with You beside me,
I shall be undismayed;
And led by Your good Spirit,
I shall be unafraid.
Abide with me, O Savior,
A firmer faith bestow;
Then I shall bid defiance
To ev’ry evil foe. (Erdmann Neumeister, 1671-1756; LSB 587:2)
Amen.