Can we lose our salvation if we commit another sin?

You prayed, you believed, you meant every word of it. Then a week later you did the very thing you swore you would never do again, and the thought arrives before you have even finished doing it: that's it, I've lost it.

No. You have not. A Christian does not lose his salvation by sinning, and the reason has nothing to do with how bad the sin was.

Think about when Jesus died. He went to the cross two thousand years before you were born. Every sin you have ever committed was still in the future when He bore it. The sin you committed last night was as far in the future to the cross as the sin you will commit next year. If His death only covered the sins you had already committed by the day you believed, no Christian in history would have stayed saved past the first afternoon. He died once, for all of it. He is not going back to the cross to deal with the ones you have added since.

John knew this question would come, and he answered it in a single sentence.

1 John 2:1 (NKJV)

My little children, these things I write to you, so that you may not sin. And if anyone sins, we have an Advocate with the Father, Jesus Christ the righteous.

Two things stand side by side in that verse. John writes so that his readers will not sin — he never treats sin lightly. But he assumes they will sin, and he tells them what waits for them when they do: that they have an Advocate, someone called to your side to speak on your behalf, and the One speaking is the same One who died for you. Your sin does not drive Him away. It is the reason He is standing there.

The idea that a Christian stops sinning at conversion is not something Scripture teaches. John says the opposite in the same letter.

1 John 1:8 (NKJV)

If we say that we have no sin, we deceive ourselves, and the truth is not in us.

Sin remains in a believer after conversion. That is not a sign the new birth failed. God gives a new heart at once and then reshapes an entire life over years, and the reshaping is not finished on the day it begins. If staying saved depended on you generating enough strength never to fail again, you would have lost it long ago.

Two questions usually follow this one. What about Christians who go on sinning and live openly immoral lives? And what about Christians who later walk away and deny Christ altogether? Both are answered by a question that comes before them: who is a Christian in the first place?

1 John 3:6 (NKJV)

Whoever abides in Him does not sin. Whoever sins has neither seen Him nor known Him.

John is not describing single acts of sin; he is describing the settled direction of a life. The tense he uses carries the sense of ongoing, habitual practice — the person who sins and keeps sinning, who has made his peace with it and has no intention of stopping. That is how John can write 1 John 1:8 and 1 John 3:6 within a few paragraphs of each other without contradicting himself. The first describes a believer who still falls. The second describes a person who was never changed at all.

A believer sins and takes no pleasure in it for long. The Spirit who gave him new life does not let him settle there. The verse he read last week, the sermon he sat under, come back at him, and the sin he excused on Friday he cannot excuse by Monday. So he repents. He may repent over the same sin many times, and mean it every time.

None of that touches a man who has never been born again. He may regret the consequences, or fear being found out. The sin itself does not trouble him.

The second question is the harder one, because most of us know someone who once professed faith and now wants nothing to do with it. John had watched it happen too.

1 John 2:19 (NKJV)

They went out from us, but they were not of us; for if they had been of us, they would have continued with us; but they went out that they might be made manifest, that none of them were of us.

Notice what John does not say. He does not say they lost something they had. He says their leaving brought into the open what was already true of them.

That sentence needs guarding, because a frightened believer will read it and immediately turn it on himself. Falling into sin is not the same thing as falling away. Peter denied Christ three times in one night, with cursing, in front of witnesses — and he was restored and went on to lead the church. Judas walked out and never came back. The difference between them was not the size of the failure. It was that one of them belonged to Christ and the other never had. If you are afraid you have gone too far, that fear is not the mark of a Judas. A heart that has genuinely abandoned Christ does not lie awake grieving that it has abandoned Him.

Paul wrote to a church he loved with a confidence that rested on nothing they had done.

Philippians 1:6 (NKJV)

being confident of this very thing, that He who has begun a good work in you will complete it until the day of Jesus Christ;

Paul does not say you will complete it. He says He will. The work was begun by God, is carried by God, and will be finished by God on the day Christ returns. Your sin cannot cancel a work you did not start.