Last week we focused on the two big ifs in verse 6 and verse 14. Let’s put them before us again and then focus on how our life together at Bethlehem can help us fulfill the big ifs.

Verse 6b: “We are his [Christ’s] house [his household, his people] if we hold fast our confidence and the boast of our hope firm until the end.” Notice carefully. It does not say: we will become Christ’s house if we hold fast to our hope. It does say: we are his house if we hold fast to our hope. In other words, the holding fast to our hope is the demonstration and evidence that we are now his house.

Then look at the if of verse 14: “We have become partakers of Christ, if we hold fast the beginning of our assurance firm until the end.” Again, notice the wording carefully. It does not say: “We will become partakers of Christ in the future if we hold fast to our assurance.” It says, “We have become partakers [in the past] if we hold fast our assurance.” In other words, the holding fast to our assurance verifies that something real and lasting has happened to us, namely, we became partakers of Christ. We were truly born again. We were truly converted. We were truly made part of Christ’s house.

What then would be the conclusion if we do not hold fast to our assurance? The answer is not that you stop being a partaker of Christ, but that you had never become a partaker of Christ. Read it carefully: “We have become partakers of Christ if we hold fast to our assurance.” And so, “If we do not hold fast to our confession, then we have not become partakers of Christ.”

Hebrews Teaches Eternal Security

On the basis of this text I said last week that this book teaches eternal security. That is, it teaches that if you have truly become a partaker of Christ, you will always be one. He will work in you to preserve your faith and hope. Another way to say it is that if you are a child of God, you cannot cease to be a child of God. But we all know that there are many people who make a start in the Christian life and then fall away and forsake the Lord.

That kind of person is very much on this writer’s mind. He knows that happens and he deals with it in this text and how to keep it from happening. But when it happens, his explanation is not that the person really was a partaker of Christ, but that he never had become a true partaker of Christ. If we hold fast to our assurance, we have become a partaker of Christ; if we do not, then we have not become a partaker of Christ.

In other words persevering in faith and hope, holding fast to your confidence in God, is not a way to keep from losing your standing in Christ; it is a way of showing that you have a standing in Christ. That standing can never be lost, because you have it by the free grace of God, and because Christ has promised with a covenant and an oath (Hebrews 6:17–19) to keep those who are his (Hebrews 13:5; 20–21).

“If we hold fast to our assurance, we have become a partaker of Christ.”

In other words, my security and assurance is not a decision or a prayer that I remember doing in the past; my security and assurance is the faithfulness and power of God to keep me hoping in him in the future. My security is that “he who began a good work in me will complete it to the day of Christ” (Philippians 1:6).

How Can You “Fall Away from God” If You Never Were a Believer?

Now this raises several questions. One is: Well, if our failure to hold fast our hope and confidence means we never were really partakers of Christ, what are we falling away from in verse 12?

Take care, brethren, lest there should be in any one of you an evil, unbelieving heart, in falling away [or turning away] from the living God.

In what sense can there be a falling away or a turning away from God if we never truly belonged to God?

One simple answer is that there can be real and painful falling away from a fiancée that is not a falling away from a wife. I think the way the writer wants us to think about this is given in the example of the people of Israel in verses 7–11 (Psalm 95). He points out in verse 9 that the people “saw my works for forty years” and still they hardened their hearts against God (verse 8) and went astray in their hearts (verse 10).

In other words, they had seen God divide the Red Sea and show them great mercy to save them from Egypt. They had seen him give water from a rock, manna from the sky, guidance with pillars of cloud and fire, deliverance from enemies, good laws to live by, leniency for their rebelliousness. But in spite of all this, they became hard in heart and stopped hoping in God. They wanted to go back to Egypt, they made idols and they murmured. This is what the writer means by “falling away from the living God.”

They had been swept up into the mighty workings of God. They had tasted his power and benefited from his Spirit and goodness. They had been enlightened with God’s revelation way beyond any people on the earth. And they had fallen away. So it was with some of the people in New Testament times. And so it is today. These people had been swept up in the signs and wonders mentioned in Hebrews 2:4. They had tasted the power of the age to come. They had been folded into a loving people and experienced measures of the Spirit’s work in their midst and in their lives. They had glimpsed the light of the gospel. They had been baptized and eaten communion and listened to preaching and probably had done some remarkable works themselves.

But, as with Israel, their hearts became hard, and an evil heart of unbelief got the upper hand, and they began to put their hope in other things rather than Christ, and over time they fell away from all the goodness that they had been surrounded with. And Hebrews says that the explanation of this is that they “had not become a partaker of Christ.” They had partaken of certain measures of enlightenment and power and joy; but (to use the words of Jesus) there was no root to the plant and it withered, while others were choked with worries and riches and pleasures of this life (Luke 8:13–14).

In other words, you can fall away from God to the degree that you have come close to the work of God — the love of his people, the light of his word, the privilege of prayer, the moral force of his example, the gifts and miracles of his Spirit, the blessings of his providence and the daily revelation of sun and rain. It is possible to taste of these things, be deeply affected by them, and to be lost in unbelief, because Jesus Christ himself is not your heart’s delight and hope and confidence and reward. Jesus taught these things over and over to warn against false assurance. For example, he said in Matthew 7:21–23:

Not everyone who says to me, “Lord, Lord,” shall enter the kingdom of heaven, but he who does the will of my Father who is in heaven. On that day many will say to me, “Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?” And then will I declare to them, “I never knew you; depart from me, you evildoers.”

Prophesying, casting out demons, and doing mighty works in the name of Jesus do not prove that Jesus has “known” us, or that we are partakers of Christ. It is possible to do those things with a hard, unchanged heart. The evidence of “being known” by Jesus is that Jesus is our hope, our confidence, our treasure, our reward (Hebrews 10:24; 11:25–26). That is the inner reality that transforms our lives.

That’s one question: How can you fall away from or turn away from God, if you never were a partaker of Christ? And the answer is: there are many ways to partake of the nearness of God without trusting him and hoping in him and loving him. And so there are many ways to turn from Christ without having ever been a partaker of Christ himself.

How Can We Be Assured of Our Eternal Security?

So the second question is: What shall we do? How shall we know and enjoy and be assured of our eternal security? Verses 12 and 13 give two answers: one more general and the other more specific.

“Cavalier Christians need to be worried about their standing.”

First, the general answer in verse 12: “Take care, brethren, lest there should be in any one of you an evil, unbelieving heart, in falling away from the living God.” The general answer is, “Take care!” or “Take heed!” or “Look!” In other words, don’t be careless or nonchalant or inattentive about the condition of your heart. Look at it. As Paul says in 2 Corinthians 13:5, test yourselves to see if you are in the faith. Or like Peter says in 2 Peter 1:10, “Be diligent to confirm your election and your calling.”

Don’t coast or drift and take your perseverance in faith for granted. All kinds of alternative passions are making war on your soul every day to steal your faith and replace Christ with other treasures. Take care! Be on the lookout! Be earnest! Be watchful over your heart. As Proverbs 4:23 says, “Watch over your heart with all diligence, for from it flow the springs of life.” That’s the answer of verse 12. Take heed!

Someone may ask, “Well, if I am a true partaker of Christ, as I believe I am, why do I have to take heed and be so vigilant, when you have said that I am eternally secure and can’t lose my standing in Christ?” I think the question assumes something that the New Testament says is not true. It assumes that God’s way for his chosen ones to get to heaven is without vigilance and watchfulness and self-assessment and diligent use of means. But in fact, Jesus says, in Luke 13:24, “Strive to enter by the narrow door; for many, I tell you, will seek to enter and will not be able.” And Peter says, “Be sober, be watchful, your adversary the devil prowls around like a roaring lion seeking someone to devour” (1 Peter 5:8). The truth is not that true Christians don’t have to be vigilant and watchful over their hearts; but that you can know you are a true Christian if you are vigilant and watchful over your heart.

It’s the cavalier Christians who need to be worried about their standing. It’s those who were baptized and walked an aisle or prayed a prayer and took communion and came to church, but do not love Jesus or count him their dearest treasure or bank their hope on him and look forward to seeing him and can say, “To live is Christ and to die is gain.” These are the self-assured ones who need to feel insecure (see Deuteronomy 29:19).

They are people, often in the church, who treat their salvation like a vaccination. They got the vaccination years ago and assume all is well without giving any thought to the dangers of unbelief around them. They say, “I got inoculated against hell when I was eight days old — or six years old.” And so getting to heaven is not a matter of vigilance over their heart to keep it from becoming hard and unbelieving. It’s simply a matter of making sure that the inoculation happened. These are the ones that are in tremendous danger.

That’s the first answer to how we stay assured of our eternal security: Take heed to your heart. Guard against unbelief. That is, be vigilant to maintain your confidence and hope in Christ against all competing treasures.

The second answer is more specific in verse 13: “But encourage [or exhort] one another day after day, as long as it is still called ‘Today,’ lest any one of you be hardened by the deceitfulness of sin.” The second answer is that eternal security is a community project. What shall we do at Bethlehem to avoid an “evil heart of unbelief” and not be hardened by the deceitfulness of the sins that tempt us every day to treasure them more than we treasure Jesus?

How Does the Church Help Us Avoid an “Evil Heart of Unbelief?”

The answer is that we must be the church for each other. And what is the main thing that the church does for each other? We speak to each other in ways that help us not be deceived by the allurements of sin. Or to put it positively, we speak to each other in ways that cause us to have hearts of faith in the superior value of Christ over all things. We fight to maintain each other’s faith, by speaking words that point people to the truth and value of Jesus. That’s how you guard against an evil heart of unbelief. Unbelief means failing to rest in Jesus as your greatest treasure. So helping each other believe means showing people reasons why Jesus is more to be desired and trusted and loved than anything else.

Right here is one explanation why God would ordain that the Christian life be a life of individual and community vigilance, and why he would plan for eternal security to be a community project. The explanation is that this way of living the Christian life makes the glory of Christ the center of all our interaction. If eternal security were like a vaccination, then Christ might be honored on the day of the inoculation, but after that he may be forgotten, the way we forget our vaccinations. But not so if eternal security involves a daily battle against unbelief where the weapons of victory are faith-building exhortations about the trustworthiness of Christ and the greatness of Christ and the value of Christ over all things.

“Unbelief means failing to rest in Jesus as your greatest treasure.”

If we must speak this way to each other every day to make sure that we all keep trusting him, then he is made much of day after day. He is always spoken of and always the center of attention. So God ordains that eternal security be a community project because he does not want his Son forgotten like a vaccination, but celebrated daily as the greatest treasure in the universe.

Now it is plain from verses 12 and 13 that something more than preaching is in view here. I try to do this in my preaching — exhort you weekly not to have an evil heart of unbelief. But this text says two things more than that. One (in verse 13) is that this exhorting is to happen “day after day,” not just once a week. And the other is it is to be done by “one another” (verse 13) — that is, you are to do it to each other, not just get it from the preacher.

This conviction — that such a one-another ministry is utterly crucial to your perseverance in faith, and your salvation — this conviction is the reason that the elders have decided to dial up the small group ministry this fall at Bethlehem. We believe there is no better way in a church this size to encourage this kind of corporate fight of faith than to make a larger place for small groups and work toward large participation.

That is why beginning in September every Sunday night will be set aside for small groups and every Wednesday night will be devoted to connecting with each other at midweek over food, worshiping together as a church, telling faith-building stories of what God is doing in the groups, and teaching the word of God to our children, youth, and adults lest there be in any of us an unbelieving heart leading us to fall away from the living God.

I am excited about the ministry potential of both these moves — (1) the dialing up of small groups by making every Sunday night available in the hope that many groups will become more and more like ministry teams that exhort each other every day; and also (2) the Wednesday evening pattern of fellowship, worship, teaching, and stories of God’s present power.

I urge you with all my heart to take this passage of Scripture seriously as you ponder whether your life matches this pattern of Christian living. Might not regular gathering with a small group of believers, who are bent on fighting for each other’s faith, bring you to an enjoyment of assurance and security beyond anything you have known and release you for courageous witness and ministry in the world? I think that is what God is calling us to.