The Certainty of Eternal Life | 1 John 5:13-21 | This Week’s Devotions

This week's devotional closes out our thirteen-week journey through 1 John, walking alongside the final sermon in our "Walking in the Light" series, "The Certainty of Eternal Life," from 1 John 5:13-21. Over five days, we'll sit with the certainties John gives every believer: certainty of eternal life, confidence in prayer, the call to intercede for one another, three "we know" statements that anchor our faith in God's revealed truth rather than our own feelings, and John's closing charge to guard our hearts from every false god. If you've walked through 1 John with us since early summer, this is the landing point all of it has been building toward. If you're just joining, there's no better place to end than where certainty itself begins.

Day 1: That You May Know

Scripture Reading: Romans 8:15-39 & 2 Timothy 1:8-12
Reflection:

John states his purpose for writing with directness that should settle something for every reader: "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." Not hope. Not feel. Not assume. Know. The verb he uses is oida, the word for settled, certain, complete knowledge. He is not promising a slightly more confident probability. He is pointing to a certainty grounded not in introspection but in what God has said about his Son.

Paul in Romans 8 grounds that certainty in the Spirit's own testimony. The Spirit you received is not a spirit of slavery driving you back into fear, but the Spirit of adoption by whom you cry "Abba, Father." The Spirit himself bears witness with your spirit that you are a child of God. And then Paul stakes his confidence against the entire created order: he is fully persuaded that neither death nor life, neither angels nor rulers, neither things present nor things to come, nor anything else in all creation, will be able to separate us from the love of God in Christ Jesus our Lord.

Paul tells Timothy he is not ashamed of his suffering because he knows whom he has believed, and he is convinced that God is able to guard what has been entrusted to him. The certainty is a conviction about the character and faithfulness of the God who called him, not self-generated confidence. This is the kind of knowing John wants to give his readers, not a feeling that fluctuates with circumstances, but an anchor that holds because it is fastened to someone who cannot change, cannot lie, and cannot lose what is his own.

Questions to Consider:

John says he writes so that believers may know they have eternal life, not hope or assume, but know. Do you actually live with that kind of settled certainty, or does your sense of standing before God fluctuate with how well your spiritual life is going? What would it take to anchor your assurance more firmly in what God has said rather than in how you feel?

Paul is fully convinced, that nothing can separate him from God's love. That persuasion came through suffering and imprisonment, not through comfortable circumstances. How does suffering sometimes clarify rather than undermine confidence in God's faithfulness?

Paul says he knows whom he has believed and is convinced God will guard what has been entrusted. The certainty is about God's character, not his own. Where in your spiritual life do you most need to shift your confidence from your own faithfulness to God's?‍ ‍

Day 2: Confidence in Prayer

Scripture Reading: Matthew 7:7-11 & Philippians 4:6-7
Reflection:

Jesus makes prayer sound almost embarrassingly simple in Matthew 7: ask and it will be given, seek and you will find, knock and the door will be opened. He grounds it in the relationship between a father and his child. Which of you, if your son asks for bread, will give him a stone? If earthly fathers, despite being evil, know how to give good gifts to their children, how much more will the Father in heaven give good things to those who ask him?

Paul's instruction to the Philippians is equally concrete: in everything, by prayer and supplication with thanksgiving, let your requests be made known to God. There is no category of concern too small or too large. And the result Paul promises is not the granting of every specific request but something more fundamental: the peace of God, which surpasses all understanding, will guard your hearts and minds in Christ Jesus. Prayer changes the person praying, not only the circumstances being prayed about.

John says in 5:14-15 that the confidence believers have before God is this: if we ask anything according to his will, he hears us. The qualification is not a loophole that undermines confidence. It is a reminder that praying according to God's will is praying in alignment with the Father who knows better than we do what we actually need. The child who trusts the father's wisdom asks freely, knowing that the answer, whatever form it takes, is given in love.

Questions to Consider:

Jesus compares God's willingness to give good gifts to the instinct of a good earthly father. How does your experience of your own father, for better or worse, shape the way you instinctively approach God in prayer, and where might those instincts need to be corrected by the truth of who God actually is?

Paul says bring everything to God in prayer, nothing is too small or too large. What categories of concern do you tend to leave out of prayer, either because they seem too trivial, too hopeless, or because you feel you should handle them yourself?

John says confident prayer is prayer according to God's will. Rather than being a source of anxiety about whether you are praying the 'right' things, how can that condition actually free you to pray more boldly, knowing that the Father who hears you also shapes what you need?‍ ‍

Day 3: Praying for One Another

Scripture Reading: James 5:13-18 & Ezekiel 22:30
Reflection:

James's instruction about prayer in the community of believers is startling in its practicality. Is anyone among you suffering? Let him pray. Is anyone cheerful? Let him sing praise. Is anyone sick? Let him call for the elders of the church, and let them pray over him, anointing him with oil in the name of the Lord. Confess your sins to one another and pray for one another, that you may be healed. The effective, fervent prayer of a righteous person has great power.

James points to Elijah as the model, not an angelic being or superhuman saint, but a man with a nature like ours. He prayed fervently that it would not rain, and for three and a half years it did not. He prayed again, and the heaven gave rain. The implication is meant to be stirring rather than intimidating: if that is what prayer can accomplish through an ordinary person with a nature like yours, then what might God do through your prayers for the people around you?

John addresses the specific case of intercession for a sinning brother in 5:16, calling believers to pray for those caught in sin that does not lead to death. This is not the prayer of a detached observer but the engaged, costly, persistent intercession of someone who cares about another person's soul. Ezekiel records God's grief at finding no one willing to stand in the gap and intercede for the land before him. Intercessory prayer is not a passive response to crisis. It is active spiritual engagement on behalf of another, standing between their present condition and God's purposes for them.

Questions to Consider:

James says confess your sins to one another and pray for one another; mutual confession and mutual intercession are practices of the community, not just the individual. What would it take for that kind of vulnerable, engaged prayer to characterize your closest relationships within the church?

James points to Elijah, a man with a nature like ours, as the model for powerful prayer. What does it do to your confidence in prayer to know that the person James holds up as an example of effective intercession was not fundamentally different from you?

Ezekiel describes God searching for someone to stand in the gap through intercession, and grieving when no one was found. For whom in your life are you currently standing in the gap through persistent, engaged prayer? Who needs you to take up that role on their behalf?

Day 4: We Know

Scripture Reading: Job 19:25-27 & 2 Corinthians 5:1-9
Reflection:

Job speaks from the depths of suffering that most people never reach. He has lost everything, his body is wasting, his friends have turned against him, and his sense of God's presence has been swallowed by apparent abandonment. And out of that darkness comes one of the most astonishing declarations of faith in all of Scripture: "For I know that my Redeemer lives, and at the last he will stand upon the earth. And after my skin has been thus destroyed, yet in my flesh I shall see God." He has a conviction that the God who made him will one day vindicate him face to face. The knowing preceded the understanding.

Paul writes in 2 Corinthians 5 from his own experience of bodily suffering and begins with a "we know": we know that if the tent of our earthly home is destroyed, we have a building from God, a house not made with hands, eternal in the heavens. The groaning of present suffering does not undermine the certainty of what awaits. It sits alongside it, honestly acknowledged and genuinely painful, but not the final word. We walk by faith, not by sight, but walking by faith is still walking, still moving confidently in a direction.

John closes his letter with a remarkable cluster of "we know" statements: we know that the Son of God has come, we know that we are from God, we know that we are in him who is true. Three anchors of certainty, each grounded not in the believer's spiritual achievement but in what has been revealed in history, confirmed by the Spirit, and received through faith. The certainty John offers is not the certainty of having all the answers. It is the certainty of knowing the one who does.

Questions to Consider:

Job's declaration 'I know that my Redeemer lives' came out of the deepest suffering imaginable, not from a place of comfort and clarity. How do some of the most unshakeable expressions of faith emerge from darkness rather than ease, and what does that tell you about how certainty is forged?

Paul says 'we know' in the middle of circumstances that would rationally undermine confidence. Where in your own life do you most need to anchor your 'we know' against circumstances that are pressing in the opposite direction?

John's 'we know' statements are grounded in what God has done and revealed, not in what the believer has achieved. How does basing your certainty in revealed fact rather than felt experience actually produce a more stable and durable faith?‍ ‍

Day 5: Keep Yourselves from Idols

Scripture Reading: Isaiah 44:9-20 & Ezekiel 36:25-27
Reflection:

Isaiah's portrait of idolatry is one of the most searching and darkly comic passages in the Old Testament. A man cuts down a tree. He uses half the wood to cook his food and warm himself by the fire. With the other half he makes a god, falls down before it, and prays: "Deliver me, for you are my god!" Isaiah's verdict is withering: no one stops to think that they are worshiping the ash left from what they burned to keep warm. A deluded heart has led them astray. They are feeding on ashes, investing their deepest trust in something that cannot hear, respond, or save.

Ezekiel's word from God goes to the root of the idol problem from the other direction. The solution to a heart that keeps manufacturing idols is not more willpower or better spiritual discipline. It is a new heart. "I will give you a new heart, and a new spirit I will put within you. And I will remove the heart of stone from your flesh and give you a heart of flesh. And I will put my Spirit within you." The idol problem is a heart problem, and only God can fix the heart.

John's final word, "Little children, keep yourselves from idols," is the perfect closing note for a letter that has been about knowing the true God as opposed to the many false versions that compete for the heart's allegiance. Having established who the true God is, who Jesus is, what love is, what life is, and what certainty looks like, John ends with a warning every generation needs: the human heart is always manufacturing alternatives. The remedy is not vigilance alone. It is the ongoing, Spirit-given gift of knowing the one who is true, in Jesus Christ his Son.

Questions to Consider:

Isaiah's idol-maker cannot see what he is doing; a deluded heart has led him astray. What are the modern equivalents of the idol he describes, things we invest with the trust, the hope, and the devotion that belong only to God? Which of those is most active in your own life right now?

Ezekiel says the cure for a heart that makes idols is a new heart given by God, not more willpower. How does that diagnosis change the way you approach the idols in your own life, moving from self-discipline as the primary strategy toward something more rooted in the Spirit's work?

As you reach the end of this thirteen-week journey through 1 John, from the eyewitness testimony of chapter 1 to this final warning, what is the most significant thing God has shown you about himself, about yourself, and about what it means to walk in the light?

Continue Walking in the Light

This devotional closes out our time in 1 John, but the truths it points to don't. If you'd like to revisit any part of the "Walking in the Light" series, you can find the full 1 John series here. And if you're looking for more to grow in the Word, our sermon archive has messages from most of our past series at First Reformed.