Know the truth in order to beware of error

Sermon for Trinity 8

Jeremiah 15:19-21  +  Romans 8:12-17  +  Matthew 7:15-23

In the Gospel we have a simple but solemn command from Jesus: Beware of false prophets. How serious is this command? Well, it’s as serious as a wolf that’s allowed to sneak into a sheep pen. What will happen if a ravenous wolf gets in close to the sheep? You know what will happen. The sheep will be torn to pieces and killed. The time to beware is before the wolf gets in, not after.

Now, false prophets can refer to any who pretend to speak for God or about God but end up saying things that aren’t true. Even the evolutionary atheists are false prophets; they proclaim that God doesn’t exist, or that He didn’t create the universe in six days. So, yes, beware of them.

But Jesus isn’t talking about atheists in our Gospel. He isn’t even talking about pagan religions. He’s talking about people who try very hard to look like sheep, who enter into the Christian Church looking and sounding like Christians. He’s talking about people who call Him, “Lord.” But inside, Jesus says, they are ravenous wolves.

False prophets teach false doctrines. That’s what Jesus means when He says, You will know them by their fruits. An apple tree produces apples. A crabapple tree produces crabapples. A true prophet produces doctrine that’s good. A false prophet produces doctrine that’s bad.

Holy Scripture compares false doctrine to leaven, like yeast. Now, if you want to leaven a batch of dough, fine. But if you don’t, if you must have an unleavened batch of dough—which is what God requires of His Church when it comes to His doctrine—, then don’t let even the tiniest bit of yeast get mixed in. Because if you do, it will be absolutely impossible to get it back out again, won’t it?, or to keep a part of the dough pure. Once the yeast gets mixed in, it can never be removed. As St. Paul writes, A little leaven leavens the whole lump. So, Jesus says, beware of false prophets who teach false doctrine.

Now, I’ve heard before from former members, and I know that other Lutheran pastors hear this from time to time, even from some in their own congregations: Why do you have to talk about other denominations? Why do you have to focus on Lutheranism at all? Why can’t you just say positive things about the Bible and about other churches?

The answer is simple: Because you’ve been given a command by the Lord Jesus, and so have I. Beware of false prophets. He isn’t at all concerned about how uncomfortable His command may make you feel, or about hurting the feelings of those who sit at the feet of false teachers to learn from them. He sees what you do not—the grave spiritual danger that prowls at your door and will rip you apart if false doctrine is allowed to sneak in and lodge itself in your heart.

Now, that said, you know we don’t sit here week after week bashing other churches or other Christians. That’s not our practice. In fact, we give thanks to God for all true Christians, wherever they may be in the world, and we pray for those who are exposed to false doctrine, that they may be freed from it.

But in the course of the Christian life, if we wish to stay on the path, then we do have to know where the edges of the path are and what dangers lie to the right and to the left and where our enemy has historically tried to lead people astray. The devil, with God’s permission, has filled the world with the dark smoke of false teaching, even as he has sown false prophets and doctrines of demons in every city, in every place where the true Gospel has also been preached. God permits it as a punishment on mankind for despising His Word and as a tool to sharpen His faithful people by driving them ever back to His Word.

Now, who are the false prophets to beware of? I won’t make a list for you. I don’t need to. They’re everywhere. All of you who have been confirmed here have studied the Scriptures and have confessed that the Lutheran Confessions, as far as you know them, are in agreement with Holy Scripture and represent the apostolic teaching of the universal Christian Church. So beware of any teaching that contradicts these Confessions. That includes everything you read on Facebook, every song on the radio, every show on TV, every book you read. They may sound nice and innocent. They may appeal to your emotions. They may even quote Scripture. But if you’re not watching out, they will lodge a notion in your mind that comes, not from God, but from the devil. So be wary and critical of everything you see and hear.

Beware also of every non-Lutheran prophet in the world. That doesn’t mean every non-Lutheran preacher is automatically a false prophet; a person could conceivably preach the pure Christian faith without ever having heard of Martin Luther. But it doesn’t usually work that way. Denominations form precisely because one disagrees with the doctrine of another. And if the Lutheran faith is nothing other than the Christian faith as it has been handed down from the apostles—which is what we believe it to be or else there’s no point in being Lutherans—then you have to beware of someone who doesn’t want to be associated with the Lutheran confession.

Of course, as you well know, the name Lutheran doesn’t inoculate someone against false teaching, does it? On the contrary, the largest Lutheran church bodies in the world—the ELCA and its partners—can hardly even be characterized as Christian anymore, much less Lutheran. And the other medium-sized Lutheran church bodies with whom we’re very familiar have their own favorite false doctrines that they won’t let go of. No, the more cunning the wolf, the more closely he will dress like the sheep. So you still have to beware.

But it gets even harder than that, doesn’t it? Even within a church body that teaches everything correctly, according to God’s Word, a person can go off on his own and begin to teach falsely. So even if you’ve known a faithful pastor for years, you still have to weigh his doctrine and make sure it matches with the doctrine of Scripture.

And that’s the crux of the matter. To the extent that God enables you, you have to know and learn the Holy Scriptures. It’s impossible to even begin to beware of false prophets if you can’t distinguish the truth from error. But knowing the Scriptures is not like knowing just any book. We’re not just talking about knowing some facts. Jesus said of God’s Word that it is “truth.” And Jesus also said, “I am the Way, and the Truth, and the Life.” To know God’s Word, then, is to know Jesus. The better you know His Word, the better you know Him who loved us and gave Himself for us, that we might believe in Him and live forever with God.

So know the truth in order to beware of error. Know it, first, according to its general outline, as we review it simply in the Small Catechism: the Ten Commandments, the Apostles’ Creed, the Lord’s Prayer, Holy Baptism, the Ministry of the Keys, and the Sacrament of the Altar. If you knew only the truth as it’s confessed in the Small Catechism, you would be able to identify the vast majority of false doctrines that you encounter on a daily basis.

And then work for the rest of your life on filling in the gaps in between. Everything you need to know for your salvation is revealed in Holy Scripture and confessed in our Lutheran Confessions. And the Lord Jesus has promised His Holy Spirit to guide you into all truth, so that you know Him as He is, and so that you may do the will of the Father in heaven.

So come to church every Sunday and pay careful attention, not just to the sermon, but to every word that is said and sung. Read your Bible at home and meditate on it. Come to Bible class. Study your Small Catechism and all the Lutheran Confessions. And pray to God that He will enlighten you with His gifts and grant you wisdom to know the truth that you may also beware of error. Amen.