How to be sure you are a Christian

How can you be sure that you are a Christian? How can you know that you know? This is one of the most important questions you can ever answer in life. It is foundational to your life and growth as a Christ follower. Without the peace of mind that God loves you and that you are a child of God, you will never feel secure. You will always be tempted to doubt your faith. You will fear that you are not good enough. You will worry that you might lose your faith. Tonight I want us to answer the question once and for all. Please turn with me to 1 John 5. In verse 13 John writes,

“I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life.” (1 John 5:13).

The Apostle John uses the word “know” almost 40 times in this short letter.  Why? because the Lord wants us to know him and know that we know him. That we know our sins are forgiven. That we know we have been adopted into his family. That we know we have eternal life. That we know we will be with God for ever and ever. So how can we know? Let’s consider three tests. Three simple tests so that you can know you know.


1. The Lordship Test

“Everyone who believes that Jesus is the Christ is born of God.” (1 John 5:1a).

Do you believe Jesus is the Christ, the Messiah, the Saviour, the Son of the Living God? (Matthew 16:16). Do you believe Jesus is the Way, the Truth and the Life? Do you believe that no one comes to the Father except by Him? (John 14:6). As you read the story of Jesus’ life in the gospels, are you convinced by the testimony of eye witnesses who met Jesus? By the prophecies about him? By his miracles? By his teaching? By his resurrection? In his own eye witness account, the apostle John writes,

“Jesus performed many other signs in the presence of his disciples, which are not recorded in this book. But these are written that you may believe that Jesus is the Messiah, the Son of God, and that by believing you may have life in his name.” (John 20:30-31)

So do you believe the evidence? Did the evidence compel you to put your trust and confidence in Jesus? Have you received Jesus into your life?

“Yet to all who did receive him, to those who believed in his name, he gave the right to become children of God.” (John 1:12)

If we really believe in Jesus we will respond to Jesus call and receive his promise to come into our lives. It is important to remember though that this is a work of God – we are saved by his grace and not our faith or works.

“For it is by grace you have been saved, through faith—and this is not from yourselves, it is the gift of God—not by works, so that no one can boast.” (Ephesians 2:8-9)

That is why John writes, “Everyone who believes that Jesus is the Christ is born of God.” (1 John 5:1).

That is the first test. The Lordship test. Is Jesus your Lord and Saviour? Yes or no? The second test?

2.  The Family Test

“and everyone who loves the father loves his child as well.” (1 John 5:1b)

John spoke about this in more detail in chapter 4.

“Whoever claims to love God yet hates a brother or sister is a liar. For whoever does not love their brother and sister, whom they have seen, cannot love God, whom they have not seen. And he has given us this command: Anyone who loves God must also love their brother and sister.” (1 John 4:20-21)

You see, when we trust in Christ, we are born again.  But we are born again into a family. God’s family. If the Lordship test is invisible, the family test is visible.

If the Lordship test is about loving God, the family test is about loving God’s children. Who are your family? Who are your closest friends? We are commanded to respect and obey our parents and love our natural family. But when Jesus own family disapproved of his priorities,

“He replied… “Who is my mother, and who are my brothers?” Pointing to his disciples, he said, “Here are my mother and my brothers. For whoever does the will of my Father in heaven is my brother and sister and mother.” (Matthew 12:48-50)

Sometimes our natural family will reject Jesus and then we have a difficult decision to make. If our natural family rejects us, we have a spiritual family that will care for us. Sometimes even relationships with fellow believers are challenging because we all bring our baggage with us.  That is why Paul writes in 1 Timothy,

“Do not rebuke an older man harshly, but exhort him as if he were your father. Treat younger men as brothers, older women as mothers, and younger women as sisters, with absolute purity.” (1 Timothy 5:1-2)

When you wake up on Sundays who do you most want to be with most? Do you see Christ Church as your spiritual family? Do you love your brothers and sisters in Christ?  Do you want to hang out with them? Are you protective of them? Are you praying for them? Is being part of a church family important to you? Yes or no?

You see these tests are really very simple.

The Lordship Test: Is Jesus your Lord and Saviour?
The Family Test: Do you identify with a church family?

The third test?

3. The Paternity Test

“This is how we know that we love the children of God: by loving God and carrying out his commands. In fact, this is love for God: to keep his commands. And his commands are not burdensome, for everyone born of God overcomes the world. This is the victory that has overcome the world, even our faith. Who is it that overcomes the world? Only the one who believes that Jesus is the Son of God.” (1 John 5:2-5)

Do people see the family likeness in us? Do they look and say “you’ve got your fathers eyes!” It is not about a new ‘me’ but a new motivation. Do I want to please my father or myself? It’s not about attaining perfection but making progress. Instead of being of the world, we have overcome the world. In the world but no longer shaped and controlled by its values. Paul described his attitude.

“Not that I have already obtained all this, or have already arrived at my goal, but I press on to take hold of that for which Christ Jesus took hold of me. Brothers and sisters, I do not consider myself yet to have taken hold of it. But one thing I do: Forgetting what is behind and straining toward what is ahead, I press on toward the goal to win the prize for which God has called me heavenward in Christ Jesus.” (Philippians 3:12-14)

Can you identify with him? Is that your motivation? Is this your heartbeat? Are you becoming more like Jesus every day? Then you pass the third test.

Three simple tests of Christian assurance:

The Lordship Test: Is Jesus your Lord and Saviour?
The Family Test: Do you love your church family?
The Paternity Test: Does the family likeness appear in me?

John concludes this passage with this bold and categorical statement about the basis of assurance.

“And this is the testimony: God has given us eternal life, and this life is in his Son. Whoever has the Son has life; whoever does not have the Son of God does not have life. I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life.” (1 John 5:11-13)

Seven questions for you (and I’ll give you the answers).

1: According to this passage, where is eternal life to be found? Answer: In Jesus Christ
2: If you have Jesus Christ in your life, what else do you have? Answer: Eternal Life.
3: Can a person know that they have eternal life? Answer: Yes.
4: On what basis? Answer: On the basis of the authority of God’s word.
5: Do you know that you have eternal life? Answer?
6: On what basis?
7: Do you have the assurance of salvation?

Our assurance of salvation is based on the authority, on the truth and the trustworthiness of God’s word not our feelings. God cannot lie. God has spoken the truth. Our assurance is therefore ultimately on the basis of what God has spoken about us.

Jim Packer is the author of the classic book Knowing God. I cannot recommend it to you more highly than to say – sell your shirt to buy it. In Knowing God, Jim has a chapter about being children of God. He writes,

“To help us realise more adequately who and what, as children of God, we are, and are called to be, here again are some questions by which we would do well to examine ourselves again and again.

Do I understand my adoption?  Do I value it?

Do I daily remind myself of my privilege as a child of God? Have I sought full assurance of my adoption?

Do I dwell on the love of God for me?

Do I treat God as my Father in heaven, loving, honouring and obeying Him, seeking and welcoming His fellowship, and trying in everything to please Him?

Do I think of Jesus Christ, my Saviour and my Lord, as my brother too, bearing to me not only a divine authority but also a divine-human sympathy?

Do I think daily how close He is to me, how completely He understands me, and how much, as my kinsman redeemer, He cares for me?  Have I learnt to hate the things that displease my Father?  Am I sensitive to the evil things to which He is sensitive?

Do I make a point of avoiding them, lest I grieve Him?

Do I look forward daily to that great family occasion when the children of God will finally gather in heaven before the throne of God, their Father, and of the Lamb their brother and their Lord? Have I felt the thrill of this hope?

Do I love my Christian brothers & sisters with whom I live day by day, in a way that I shall not be ashamed of when in heaven I think back over it?  Am I proud of my Father, and of His family, to which by His grace I belong?  Does the family likeness appear in me?

Do I, as a Christian, understand myself? Do I know my own real identity? My own real destiny?

I am a child of God. God is my Father; heaven is my home; every day is one day nearer. My Saviour is my brother; every Christian is my brother too.

Say it over and over to yourself first thing in the morning, last thing at night, as you wait for the bus, any time when your mind is free, and ask that you may be enabled to live as one who knows it is all utterly and completely true. For this is the Christian’s secret of — a happy life? — yes, certainly, but we have something both higher and profounder to say. This is the Christian’s secret of a Christian life, and of a God-honouring life… May this secret become fully yours, and fully mine.”

We have asked the question tonight, “How to be sure I am a Christian?” I hope you know the answer.  Lets pray. Let’s say ‘thank you’ for the privilege of knowing God and being adopted into his family.

“Thank you heavenly Father my creator and sustainer, for making me your child and for adopting me into your family. Thank you Lord Jesus Christ for dying on the cross in my place to take away my sins and give me eternal life. Thank you Holy Spirit for the assurance you will never leave me and will help me grow to become more like Jesus every day.  Amen”.

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