1 John 5:13-21 - That We May Know

Introduction: How It’s Made

Well, church, how are we doing today? You made it out in the rain! I am so proud of you. It would have been much easier to call in sick or join us online—and we are certainly grateful for those of you joining us digitally—but it’s great to see you here. My name is Mike, and I’m one of the teaching pastors here at The Well. Today, I have the great privilege of landing the plane on the book of First John. I hope that makes you both excited and sad at the same time.

If you have your Bible, I want to invite you to turn to First John chapter five. We’re going to look at verses 13 through 21 together as we walk through this book for the last time.

As you turn there, I wonder how many of you are fellow nerds like me. Any of you enjoy the show How It’s Made? It’s been on the Discovery Channel for twenty years. I want you to know what you’re confessing to—you are nerds if you like this show! It is exactly what it sounds like: a show that walks you through how things are made. It explores how they make a fishing lure or how a bicycle tire comes to be. I find it fascinating. All these things in my daily life that I buy at the store, the show takes a deep dive into how they came to be. It allows me to appreciate the significance and the value of those things in a deeper way.

In a lot of ways, that is how we are going to navigate this message today. John is doing a deep dive into our salvation. In the very first verse we’re looking at, he puts it all on the table and reminds us why he penned this letter in the first place.

1 John 5:13 (NASB)

These things I have written to you who believe in the name of the Son of God, so that you may know that you have eternal life.

John says, “This is why I write to you.” In the midst of all these false teachers who have come into the church like a sinkhole, attempting to erode the foundation of your faith, I want to remind you: for those who believe in the name of the Son of God, you may know that you have eternal life. He is seeking to affirm that this group of believers has the right gospel and that they are not to be deceived.

The Mechanics of Belief

There are three words in that verse that are critical to our understanding. The first is a word we visited last week: believe. John talks about this as being core to the gospel. Belief isn’t simply something that happens in our heads—an intellectual agreement that something is true—it goes beyond that. It is a belief of putting faith into something; it is full trust.

Remember the chair illustration from last week? It’s one thing to say, “I believe this chair will support my weight,” but it’s a very different thing to actually sit in the chair and demonstrate that you are removing trust in yourself and placing your full weight on the chair. That is belief. That is what John is saying. For those who have done that—who have believed in the name of Jesus and His finished work—you can know you have eternal life.

Notice that if there were more to it than belief, John would have said it here. He doesn’t say, “Believe and get baptized,” or “Believe and clean up your life.” He says believe, and that is it. Paul says the same thing in Ephesians: for by grace you have been saved through faith, and that not of yourselves, it is a gift of God.

That belief results in the second word: knowing. This is cognitive knowledge and assurance. Six times in this passage, John reminds us of this. This knowledge is the “why,” and “eternal life” is the “what.” In John’s worldview, eternal life isn’t just something we look forward to; it’s something that happens now. You are secure today, tomorrow, and for eternity.

The Great Exchange: Imputation

This idea of assurance is all over the New Testament. We see words like forgiven, saved, reconciled, justified, and adopted. Almost always, these words are in the past tense. It is done. Your salvation is an event that has already occurred. You cannot lose it.

But how can I say that with such confidence? It has nothing to do with me or you; it has everything to do with the finished work of Christ and what God accomplishes in us when we believe. When we believe, God does something behind the scenes that seals us in this state forever. To see this, let’s look at Romans chapter four, where Paul uses two famous Old Testament characters to illustrate what happens when we believe. The first is Abraham.

Romans 4:3 (NASB)

For what does the Scripture say? ‘ABRAHAM BELIEVED GOD, AND IT WAS CREDITED TO HIM AS RIGHTEOUSNESS.’

Abraham believed God, and it was credited to him as righteousness. That word “credited” is a bookkeeper’s term. God takes from one account and puts it into another. On the basis of Abraham’s trust, God imputes righteousness into his account.

When I was in college, I tended to run out of money before I ran out of month. I’d call my parents and say, “Hey, I have seven dollars in my bank account, and I’d really like to eat for the rest of the month.” My parents would graciously take their hard-earned money—money I didn’t earn—and credit it to my account. When I opened my bank app, that money was actually there. It was real. I could buy a sandwich because it was mine, even though I didn’t earn it. That is what God does for us.

Romans 4:5 (NASB)

But to the one who does not work, but believes in Him who justifies the ungodly, his faith is credited as righteousness,

But there is another side to that coin, and for that, Paul points to King David.

Romans 4:6-8 (NASB)

just as David also speaks of the blessing on the man to whom God credits righteousness apart from works: ’BLESSED ARE THOSE WHOSE LAWLESS DEEDS HAVE BEEN FORGIVEN, AND WHOSE SINS HAVE BEEN COVERED. ‘BLESSED IS THE MAN WHOSE SIN THE LORD WILL NOT TAKE INTO ACCOUNT.’

What is the difference? Abraham had something put into his account that wasn’t there (righteousness). David had something taken out of his account that was there (sin). This refers to the time David committed adultery and murder. God took that sin out of David’s account and imputed it to another.

Abraham is the picture of grace: getting what we don’t deserve. David is the picture of mercy: not getting what we do deserve. When we believe, God imputes the righteousness of Christ to us, and He credits our sin to Christ on the cross. The result is peace.

Romans 5:1 (NASB)

Therefore, having been justified by faith, we have peace with God through our Lord Jesus Christ,

When you believe, you are sealed. Paul tells the Ephesians that we are sealed with the Holy Spirit of promise, who is a pledge—a deposit—of our inheritance. Like a king sealing a letter with a signet ring, God says, “It is done.”

Confidence in Prayer

Having this assurance changes how we live. Look at verses 14 and 15.

1 John 5:14-15 (NASB)

This is the confidence which we have before Him, that, if we ask anything according to His will, He hears us. And if we know that He hears us [in] whatever we ask, we know that we have the requests which we have asked from Him.

This belief results in the confidence that we can come before our Father and ask anything according to His will. This isn’t a blank check for a Lamborghini or a house in Pismo. It means praying in accordance with His nature and His word. When we pray according to His will, He hears us—and in this context, “hearing” means moving into action on our behalf.

John then moves into a very difficult section regarding praying for others who sin.

1 John 5:16-17 (NASB)

If anyone sees his brother committing a sin not [leading] to death, he shall ask and [God] will for him give life to those who commit sin not [leading] to death. There is a sin [leading] to death; I do not say that he should make request for this. All unrighteousness is sin, and there is a sin not [leading] to death.

This is one of the most difficult passages in the Bible. What is a “sin leading to death”? Does “brother” mean a fellow Christian or a false teacher? There are several views. Some think it’s apostasy (losing salvation), but we’ve already seen that’s biblically impossible. Others think it’s a specific sin so heinous that God takes a believer’s physical life, like Ananias and Sapphira. Others think it’s the blasphemy of the Holy Spirit, which was unique to the time Jesus was physically on earth.

Here is where I land: I think John has both believers and unbelievers in mind. For us as believers, there is no sin that leads to eternal death because we are secure in Christ. But the “sin leading to death” is the final rejection of the gospel. If you reject the only means of forgiveness, there is no forgiveness. John is likely thinking of the false teachers who left the church and were actively deceiving people. He says their fate is sealed; don’t even worry about praying for them in that hardened state.

For us, the lesson is that sin is serious business. Whether it leads to eternal death or not, every sin is an affront to God. It needs to be confessed and repented of so we can continue to abide in Him.

Four Things We Know

As John closes, he uses the phrase “we know” three times to summarize our security.

1 John 5:18 (NASB)

We know that no one who is born of God sins; but He who was born of God keeps him, and the evil one does not touch him.

First, we have a new nature. We don’t live in habitual, unrepentant sin anymore. Second, we are safe. Jesus keeps us, and the evil one cannot snatch us out of His hand.

1 John 5:19 (NASB)

We know that we are of God, and that the whole world lies in [the power of] the evil one.

Third, we have a new identity. We are “of God,” while the rest of the world lies in the power of the evil one. We are no longer under that control.

1 John 5:20 (NASB)

And we know that the Son of God has come, and has given us understanding so that we may know Him who is true; and we are in Him who is true, in His Son Jesus Christ. This is the true God and eternal life.

Fourth, we know the real Jesus. In an age of deception, we know the True One.

Then, John ends with a bit of a curveball.

1 John 5:21 (NASB)

Little children, guard yourselves from idols.

Why end with idols? Because an idol is anything that over-promises and under-delivers. In the midst of false teachers and deceptions, John says: “You know the truth. You know who you are. Don’t let your hearts be drawn away to anything else.”

Closing Challenge

To the believer: remember how your salvation was made. You are secure. That confidence doesn’t come from your performance; it comes from what God did behind the scenes. So, let’s learn to abide in Him. Let’s not move toward “shoulds” and moralism; let’s walk in the Spirit.

And to the unbeliever: I want to invite you to “sit in the chair.” Accept the greatest offer in human history. You cannot pay for your own sin, but Jesus already did. Don’t just believe it intellectually; trust Him with your life. Today is the day to consider Christ afresh.

Father, thank you for this incredible, hard book that exalts Christ. We are so grateful for a finished salvation. Thank you that we are your children and can come boldly before you. I pray for anyone here who hasn’t yet put their faith in Jesus. Stir in their hearts to take that step of belief and find eternal life in Christ alone. In His name we pray, Amen.