If you’ve ever shared doubts with a Christian friend about whether you can know that you’ve received eternal life or will go to heaven one day, it’s likely they’ve read to you 1 John 5:13. That’s the verse which says, “I write these things to you who believe in the name of the Son of God that you may know that you have eternal life.” It’s a great verse of assurance that promises us that we can know that we have eternal life. There’s no need to be left guessing. The promise is made to those who believe in Jesus and it has calmed the fears of countless believers. I think it’s a great verse and it’s not wrong to share it with people who have doubts. The problem is that it can be read and applied too simplistically. That’s because it’s a summary statement that comes at the end of a 5-chapter book that has given a series of tests of true and false faith. And so 1 John 5:13 needs to be understood alongside those other tests. The book of 1 John gives at least four tests, alongside our faith in Jesus, that are given to reassure us of our salvation. Let me share them with you.

1. Assurance of salvation is not for those who won’t admit sin in their lives.

At the heart of the gospel is a Saviour who was sent to rescue sinners. So, it’s not surprising to see John write that those who won’t admit that their sin should have no assurance of salvation. In 1:8, he says, “If we say we have no sin, we deceive ourselves, and the truth is not in us” and in verse 10, “If we say we have not sinned, we make him a liar, and his word is not in us.” A Christian is someone who admits their sin and knows that they need forgiveness rather than denying their sin and trying to show that they’re good enough for God. If you don’t see or admit your sin, you can’t have assurance from the Bible that you have eternal life.

2. Assurance of salvation is not for those who refuse to deal with sin in their lives.

We’ve just seen that John expects honesty rather than perfection in true believers. At the same time, someone whose faith in Jesus doesn’t lead them to turn away from sin when they recognize it can’t have the assurance that their sins are forgiven. In 1:6, for instance, John writes, “If we say we have fellowship with him while we walk in darkness, we lie and do not practice the truth.” If you claim to believe in Jesus but don’t live like it, then your claim to true faith isn’t genuine. He states the same thing even more bluntly in 2:4, “Whoever says “I know him” but does not keep his commandments is a liar, and the truth is not in him.” Verses like these, along with others (2:9, 15, 3:6, 10, 4:20), could easily create more confusion than is warranted. A person who trusts in Jesus isn’t going to stop sinning all of a sudden at the moment of their conversion. Growth takes time. And while some sins can be easily abandoned, everyone has certain sins which are more stubborn than others. A Christian will continue to stumble in sin, but sin should no longer characterize their life. There will be setbacks in the war against sin, but a true Christian is in the battle. If you refuse to deal with your sin, you can’t have assurance from the Bible that you have eternal life.

3. Assurance of salvation is not for those who reject the church.

In an age where more and more people identify as “spiritual but not religious” and where people claim to “believe in Jesus” but don’t want anything to do with the church, John’s words come as a shock. In 2:19, he says, “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 it might become plain that they all are not of us.” He’s addressing people who had been baptized, attended church and seemed to go along with everything for a while and then checked out. And he’s saying that their rejection of the church showed that their faith wasn’t real. He’s not talking about people who have merely changed churches but who have instead walked away from the church altogether. He states the same idea positively in 3:14, “We know that we have passed out of death into life, because we love the brothers.” Love for the people of God and fellowship with the family of God is good evidence that your faith is genuine. If you reject the church, you can’t have assurance from the Bible that you have eternal life.

4. Assurance of salvation is not for those who deny the Bible’s essential teachings about Jesus and the good news.

The final test that John gives is related to doctrine: what a person believes. In 4:2, he says, “every spirit that confesses that Jesus Christ has come in the flesh is from God,” and in 4:15, he adds, “Whoever confesses that Jesus is the Son of God, God abides in him.” If you reject Jesus’ humanity or His divinity, you can’t have assurance from the bible that you have eternal life. Just saying that you believe in Jesus matters very little if the Jesus you believe in is a purple alien from Mars! Christian assurance is for those who hold to the Bible’s essential teachings about who Jesus is and how a person can be saved.

These four tests give context to John’s words in 5:13, but the essence of that verse shouldn’t be lost. If you’ve put your faith in Jesus alone for your salvation, you can know that you have eternal life. You shouldn’t spend your days in uncertainty. Just be sure that yours isn’t a faith that denies your sin or refuses to deal with it or rejects the church and orthodox Christian doctrine.

In awe of Him,

Paul