What We Can Know for Sure - Troy Postlethwait

Turn to John chapter 8, and we’re going to consider verses 31 through 36. In this passage, Jesus is speaking to the Jews who believed in Him. And He tells them something powerful—something that still applies to us today.

“If you abide in My word, you are My disciples indeed. And you shall know the truth, and the truth shall make you free.” — John 8:31–32

I want to talk to you about things we can know for sure from Scripture. You see, we live in a world where a lot of people are uncertain about truth, where they say truth is relative or unknowable. But according to Jesus, there are things that you and I can know—things that matter eternally.

Jesus said it Himself: “You shall know the truth.” That truth has the power to set us free—not just from confusion, but from the slavery of sin. As He explains in verse 34, “Whoever commits sin is a slave of sin.” But if the Son makes you free, “you shall be free indeed.”

Truth isn’t just about facts—it’s about Christ. And when we abide in His word, we come to know Him and what He desires for our lives. Peter wrote in 1 Peter 1:22–23 that our souls are purified by “obeying the truth.” So it’s not enough to just know it—we’re called to obey it.

There’s no mystery about what God requires for salvation. Mark 16:16 says, “He who believes and is baptized will be saved.” And in 1 Peter 3:21, Peter makes it clear—“baptism now saves us.” Just like 2 + 2 = 4, the steps to salvation are simple and understandable.

We can also know that we know Christ by whether or not we keep His commandments (1 John 2:3). Jesus said in John 8:31, “If you abide in My word, you are My disciples indeed.” That’s how you know. It’s not based on feelings—it’s based on obedience.

Turn to John 9:31. When the formerly blind man is being questioned, he says something powerful:

“Now we know that God does not hear sinners; but if anyone is a worshiper of God and does His will, He hears him.”

That’s something we need to really think about. If someone is living in rebellion to God—unrepentant, outside of Christ—God doesn’t promise to hear their prayers. But 1 John 5:14–15 tells us that if we are in Christ, and we ask according to His will, He hears us. And in 1 Peter 3:12, Peter says, “The eyes of the Lord are on the righteous, and His ears are open to their prayers.”

So ask yourself: Am I living in a way that keeps the lines of communication open with God?

There is one church, and Jesus built it. In Matthew 16:18, He told Peter, “Upon this rock I will build My church.” He didn’t say “churches.” He said “My church.” And in Acts 20:28, we’re told that He purchased that church with His own blood.

In Ephesians 4:4–6, Paul writes there is one body, one Spirit, one hope, one Lord, one faith, one baptism, and one God. Not many—one. That body is the church, and Ephesians 5:23 tells us that Christ is the head of the church, and “He is the Savior of the body.”

So when someone asks, “Can I join your church?”—I gently explain: you don’t join the Lord’s church. Acts 2:47 says, “The Lord added to the church daily those who were being saved.” God adds you when you obey the gospel.

Once you’ve been baptized, you're raised to walk in newness of life (Romans 6:4). That means everything you did before—every sin—is washed away and forgotten by God.

So how should we live? Titus 2:11–14 tells us to live soberly, righteously, and godly in the present age. And Colossians 3:1–3 says to set our minds on things above, not on earthly things. That means living with heaven in view—not being entangled by the temporary pleasures of this world.

We Can Know That We Will Die—and Then Comes Judgment

Hebrews 9:27 tells us plainly: “It is appointed for men to die once, but after this the judgment.”

We know death is coming. We don’t know when, but we know it’s certain. And after death—judgment. 2 Corinthians 5:10 says, “We must all appear before the judgment seat of Christ, that each one may receive the things done in the body, according to what he has done, whether good or bad.”

You won’t be judged based on opinion, or popularity, or personal feelings. You’ll be judged by the word of God. Jesus said in John 12:48, “He who rejects Me and does not receive My words has that which judges him—the word that I have spoken will judge him in the last day.”

That’s why we keep urging you to read and study the Scriptures—so you’re not guessing, but knowing what the Lord requires of you.

There are some things we just can’t know in this life. But there are many things we can know—because God revealed them in His Word:

We can know the truth.
We can know how to be saved.
We can know that God hears His people.
We can know there is only one church.
We can know how to live.
We can know that we will die.
And we can know we will face judgment.

So the question is: are you ready?

If Jesus returned today—and only the Father knows when that day will come—what would you hear Him say to you?

If you need to make your life right with God, don’t wait.