The biblical way children should come to assurance of salvation is no different from the way adults should come to assurance of salvation. The Bible teaches that there are three grounds of assurance: 1. The promise of the gospel in Jesus Christ, 2. The inward witness of the Holy Spirit, and 3. The evidence of faithful good works. The Second London Baptist Confession speaks of these three grounds in 2LCF 18.2:

This certainty is not a bare conjectural and probable persuasion grounded upon a fallible hope, but an infallible assurance of faith,4 founded on the blood and righteousness of Christ revealed in the Gospel;5 and also upon the inward evidence of those graces of the Spirit unto which promises are made,6 and on the testimony of the Spirit of adoption, witnessing with our spirits that we are the children of God;7 and, as a fruit thereof, keeping the heart both humble and holy.8
4 Heb. 6:11,19
5 Heb. 6:17,18
6 2 Pet. 1:4,5,10,11
7 Rom. 8:15,16
8 1 John 3:1-3

Consider the three biblical grounds of assurance in relation to children.

1. The first ground of assurance is the promise of God in Jesus Christ.

If you trust the promise of salvation in Christ, then you can know for sure that God is your Father, and you are his child. 1 Corinthians 15:3-4 says the gospel is “that Christ died for our sins in accordance with the Scriptures, that He was buried, that He was raised on the third day in accordance with the Scriptures.” That’s a promise of absolutely free grace. There is nothing in that promise about what you’re supposed to do. It’s all about what Christ did in history to save sinners.

Sometimes children may feel that they have to work to prove that they are Christians to their parents or to their churches. Sometimes children may feel that they have to wait on some great change to happen in their hearts. They’re waiting for God to do something to make them different. The Bible teaches that the true way to assurance isn’t through slavery to works or by trying to prove yourself in some way.

Isaiah 45:22 explains the ground of assurance: “Look unto me and be saved, all the ends of the earth, for I am God and there is no other.” You can know that you are saved by looking to Jesus and crying out to God as your Father who saves you from your sins. Don’t look into yourself. Don’t look at your good works. Don’t look at your faith. Don’t look to how well you read your Bible. Don’t look at whether you love Jesus. Don’t look to your parents. Don’t look to what people at church say. Don’t look to your baptism. Don’t look to your pastor. Look to Jesus!

Christ is the ground of a child’s salvation and assurance of salvation. Parents should ask their children, “Do you believe that Jesus is enough to save you? Do you believe that Jesus is true God and true man? Do you believe He’s God the Son? Do you believe that His blood can over your sins?”

Christ and Christ alone is the reason you can be sure of your salvation. The Bible teaches that by trusting Christ, children (and all people) can have absolute assurance that they are saved. In Isaiah 49:15-16, God speaks of the assurance people have when they look to Jesus, “Can a woman forget her nursing child, that she should have no compassion on the son of her womb? Even these may forget, but I will not forget you. Behold, I have engraved you on the palms of my hands, your wails are continually before me.”

Isaiah 54:10 speaks of God’s absolute covenant with Christ, which is the ground of your assurance. “For the mountains may depart and the hills be removed, but my steadfast love shall not depart from you and my covenant of peace shall not be removed, says the LORD who has compassion on you.”

Jesus says, “Come to me all who are weary and heavy laden and I will give you rest” (Matt 11:28).

When children come to Jesus by simple faith, they can have strong assurance of salvation. Jesus even directly invites children to come to Him. He says in Matthew 13:14, “Let the little children come to me and do not hinder them, for to such belongs the kingdom of heaven.” John 3:16 says, “For God so loved the world that He gave His only begotten Son that whoever believes in Him should not perish, but have everlasting life.” If you believe in Christ, you can be sure you are saved.

The Bible teaches that there are two other grounds of assurance of salvation. These next two grounds only confirm your faith in the promise. You must never start to try to get assurance with these next two grounds. You must always start with Christ. But these next two grounds help to confirm and strengthen your assurance in Christ.

2. The second ground of assurance is the inward witness of the Holy Spirit.

We see this ground mentioned in Romans 8:16. It says, “The Spirit himself bears witness with our spirit that we are children of God.”

Many people are confused about what this verse means. It doesn’t mean that the Holy Spirit tells you directly in your heart that you are a Christian. Many people think, “If I’m a Christian, this verse says that the Holy Spirit will tell me I’m a Christian in my heart.” And so, they try listen to their hearts, but often they don’t hear anything. They can get discouraged and think they’re not Christians because they’re trying to hear the Spirit speak to their hearts.

But what this verse means is that the Holy Spirit takes the promise of Christ in the Bible, and He leads our spirits to believe and love what the Bible says about Jesus. So, when this verse speaks of the inward witness of the Holy Spirit, it’s talking about our heart’s response to the gospel of Jesus.

The Holy Spirit takes the truth of the Bible and teaches your heart that Christ died for our sins and rose from the dead. And then your heart agrees with Him! Your heart says, “Yes! Christ died and rise from the dead for sinners! I trust Him to pay for my sin!” If your heart trusts and loves the Jesus of the Bible, then that is the inward witness of the Holy Spirit.

So, how can parents help their children apply this inward witness of the Holy Spirit?

Not primarily by telling them to analyze their hearts. The Spirit’s witness is much swifter and better than that. To use an analogy, when children love their parents, they don’t have to look into their hearts to find all the different ways they love their parents. They just want them. They want dad. They want mom. They trust their parents. It’s a very simple and sincere love.

This is the simplest way to understand the inward witness of the Holy Spirit. Parents, you can ask your children, “Do you love Jesus?” And they may respond by saying, “I don’t know if I love Jesus or not.”
But then you can ask, “Do you want Jesus?” “If you want Jesus, He’s already yours.” That’s the inward witness of the Holy Spirit.

Speaking of unregenerate people, the Bible says, “None is righteous, no not one; no one understands; no one seeks for God. . . . no one does good, not even one” (Rom 3:10-12). It’s impossible for an unregenerate child to want the Jesus of the Bible, unless the Holy Spirit has changed his heart. So, if the child truly wants, or seeks, Christ, that is the beginning of the inward witness of the Holy Spirit. It may be a small beginning. But it’s a true beginning.

3. The third ground of assurance is the evidence of good works.

It’s very important that we don’t separate this ground of assurance from the promise of the gospel. The evidence of good works means that our whole life responds to the promise of the gospel. It means that we submit to Jesus as the King who saves us from our sins. He is worthy of our love and obedience. And we’re learning to live our whole life in light of the promise of Christ’s gospel.

1 John 2:3 says, “And by this we know that we have come to know him, if we keep His commandments.”

In other words, if you know Jesus, and you believe His promises, you’ll begin to live like Christ is risen from the dead and all of His promises are true.

Scripture says you can have assurance of your salvation if you keep Christ’s commandments. That word “keep” doesn’t mean “obey perfectly.” The Greek word “keep” means to observe, watch, or guard the commandments of Christ. In another sense, to “keep” Christ’s commandments means that you’re learning to live a life of repentance. The Children’s Catechism Q56 asks, “What is it to repent? A. To be sorry for sin, and to hate and forsake it because it is displeasing to God.” Learning to live a life of repentance means you’re learning to grow in love to God and love to others because He saved you and because He is your King.

So how can this help a child to have assurance? Many people wonder how the evidence of good works can possibly encourage people in their assurance. They feel like they lack good works; so, how could that help them to be sure of their salvation? But we all have such sinful hearts that we should be deeply amazed and encouraged if we faithfully obey Christ at all. It’s impossible to have any obedience if we aren’t believers. The Scripture says, “Whatever is not from faith is sin” (Rom 14:23), and “without faith it is impossible to please Him” (Heb 11:6). Unregenerate people can’t obey Christ at all, not even a little bit.

That means, if you repent at all after you sin, you should leap for joy because that’s evidence that Christ is at work in you. If children ever love their brothers and sisters at all for Christ’s sake, that should really encourage them. If they’re tempted to hate their brothers or sisters, and but they ever resist that temptation because Jesus is their King, they should be very encouraged because that is evidence that they are true Christians.

It’s important to remember that the evidence of good works isn’t the first ground of assurance. Some children don’t feel like they have any good works. Some are worried that they don’t obey God at all. They might examine their hearts, and they can only see their sin. The wrong thing for them to do would be to try to do enough good works so they can get assurance. If they did that, they would be trying to base their assurance on their good works, when it should be based on Christ. They must look to Christ.

Is Christ’s death enough to take away your sins? Is Jesus able to save you? Will you believe that Christ’s blood washes your sins away? If you believe Christ’s promises, then you must believe that you belong to Him! And then, you can start to learn from Christ about how to obey Him more and more. And when you see yourself learning from Jesus at all, you should be encouraged, and your assurance will be strengthened!

4. An illustration of how parents can help their children come to assurance of salvation.

Here’s a little girl who comes to her daddy. And she says, “Daddy, am I a Christian?”
Her daddy says, “I don’t know. I can’t tell you that. But I can tell you what the Bible says. Let me ask you some questions, ok?”
“Ok, daddy.”
“Do you believe that Jesus is true God and true man?”
“Yes.”
“Do you know that you are a sinner and that your sins deserve the anger and judgment of God?”
“Yes.”
“Do you believe that Jesus can pay for your sins through His death and resurrection?”
“Yes, daddy, I do.”
“Well, the Bible says that if you believe on Jesus, then you are saved. Do you believe on Jesus?”
“I don’t know.”
“But you just told me that you do believe Him.”
“But I can’t tell if I really believe or not.”
“Well, do you want Jesus? Do you want to be saved and do you want to be with Jesus forever?”
“Yes, I do!”
“If you want Jesus, it means you already have Him. Wanting Jesus that way is the beginning of love for Him.”
“Oh that makes me feel so much better! Thank you! I do want Jesus.”
“Let me ask you this. Do you ever obey Christ?”
“Not like I should.”
“I know that. But I’m asking if you ever obey Jesus. Do you ever try to pray, to read your Bible, to honor your parents, to love your brothers and sisters, to serve others?”
“Yes I do. But I sin a lot.”
“Daddy sins a lot too. That’s why we need Jesus to pay for our sins. And that’s why we love Jesus, because He is so good. The Bible says that if you obey Jesus at all, that should encourage you that you belong to Him! Because the Bible says that lost people never obey Christ. They don’t ever obey Jesus from a heart of love.”
“And you just told me that you want Jesus. You just told me that you believe that Jesus can pay for your sins. And now you just told me that you do obey Him sometimes!”
“All of that is how you can know you are saved! So, do you believe you are saved?”
“Well, I guess I do!”
“Daddy is so glad to hear that! Praise the Lord! He is a great Savior!”