I get this question often. It's common to have doubts about salvation. But you don't have to live in doubt. The Bible is clear about the power of the gospel. Jesus saves even the worst of sinners. I want you to have assurance of salvation.
In my experience, two things cause people to doubt their salvation: uncertainty about the mechanics of how we get saved, and indwelling sin in the believer.
1. Uncertainty about the mechanics of how we are saved
Anyone who has ever troubleshot anything knows that getting the process right always matters. I once spent thirty minutes trying to get the portable soundboard at the church to work when a seasoned member walked up and plugged it into the wall. I felt dumb. Everyone knows that experience. There is a great amount of fear of just this sort around how we get saved. Did I skip a step, or do something out of order?
The good news is that the Bible is very clear about this part. Paul says, "everyone who calls on the name of the Lord will be saved" (Romans 10:13). Jesus says, "Come to me... and I will give you rest" (Matthew 11:28). Peter said, "repent and be baptized in the name of Jesus Christ" (Acts 2:38). You can see what all of these verses have in common — Jesus is salvation. We call on him, come to him, believe in him. It's worded many ways in the Bible, but the content is always the same: we have faith in Jesus.
The mechanics of salvation have very little to do with how we are saved. Jesus does all the work. We simply believe in him. What does this look like? It may be a little different for everyone, but the core idea is faith in Jesus. Do you trust Christ for salvation? If you answer yes, that's really the only assurance you need. He alone is able to save. You don't contribute to the salvation.
To say this another way: we are saved by the object of our faith, not the quality of our faith. If I were to lie in a hammock, the hammock would hold me off the ground by virtue of its own properties. My faith in the hammock does not contribute to the hammock's power to hold me up. My faith in the hammock is nothing more than the mechanism that puts me into the hammock.
In the same way, our faith in Christ puts us into a relationship — a covenant — with God that is based on Christ's saving work, not on our ability to save or to produce fruit. Salvation depends on what Christ has done for us, not on how well we do anything.
Because of this, assurance is mostly tied to my faith in Christ, which is to say it is tied to the quality of my Savior. Assurance puts the focus on what Christ has done rather than on what I am doing. Any time I put the focus on what I am doing, I will have less assurance. When I focus on what Christ has done and is continuing to do, I will have more.
2. Indwelling sin in the believer
The other reason people lack assurance is that they have some measure of ongoing sin in their lives that seems incompatible with salvation. The question then comes down to whether they have actually believed. The issue is not whether Christ has the power and will to save, but whether we have actually put our faith in him.
In this scenario the focus has shifted from what Christ has done in the past onto what I am doing in the present. It seems inconceivable that the power of the gospel would produce such a small amount of fruit in a life. How can one be a true believer in the gospel that redeems and transforms sinners when my sin seems to go on unabated?
It must first be noted that high levels of sin are never compatible with high levels of assurance. We will always doubt ourselves when we are in the midst of sin. But we must run back to Christ. We must run into the light, not away from it. We run home to the Father; we do not stay in the pig pen.
The simple remedy
First John 2:1–2 handles this explicitly: "I am writing these things to you so that you may not sin, but if anyone does sin, we have an advocate with the Father, Jesus Christ the righteous. He is the propitiation for our sins."
I love this. The first step to take when we find ourselves in sin is not to repent, or even to confess. It's to remember Jesus. He is our advocate. He is the righteous one who saved us. He paid the price for our sins. He is the reason there is no condemnation. He set us free. He took our wrath. He redeemed us from the curse.
The first step when we sin is always to run to Christ. He is the redeemer. He is the forgiveness that we need. He is our advocate, working for us and in us to his good end. He is the source of our assurance.
The more hopeful reality behind our sin
I'll deal with this in greater depth in another post, but here is a short overview of the hope of sanctification.
We are sinners. It's not just that we sin — we are broken. We don't just do bad things, we want to do bad things. Sanctification is about dying to the old man and living in the new man by the power of the Spirit. It's a process, not a switch that gets flipped.
In the moment of sin we choose to give in to our desires. But that's the problem: we have the desires. We have the option to obey God or to indulge in sin, and we choose sin because we want it more — at least until after we have enjoyed it. Then, once the desire has diminished, we hate ourselves for ever wanting it in the first place. We tell ourselves we will never do it again, only to be right back at it tomorrow when the desire is fresh.
The daily grind feels something like this. We sin. We repent. We grieve. We sin. We repent. We grieve. We despair that we aren't changing.
But in reality there is a lot more going on. The more we walk with Christ, the more we grow in Christlikeness. That rarely means we immediately look like saints. It means we grow, however slowly, toward Christ. Each day my desire for sin slightly diminishes and my desire for Christ slightly increases. So even though I continue to sin, it may be that I'm making real progress — my desire for sin simply started so high that I have a long way to go.