How can I be sure that I am saved? How do I know for sure that when I die, I will go to heaven?

Assurance of salvation rests on two interconnected foundations: what God has objectively accomplished and what the Holy Spirit works subjectively within you.

The Objective Foundation: What Christ Has Done

Eternal life comes through Christ, and whoever possesses the Son possesses life itself (1 John 5:11–13). Salvation is by grace through faith—a gift from God, not earned by works (Eph 2:8–9). This means your standing before God doesn’t depend on your performance or feelings. If you declare that Jesus is Lord and believe God raised him from the dead, you will be saved (Rom 10:9–10). That’s the entry point.

But assurance extends beyond initial salvation. Jesus gives eternal life to his sheep, and no one can snatch them from his hand or his Father’s hand (John 10:27–29). Nothing—neither death, life, angels, demons, present, future, powers, height, depth, nor anything else in creation—can separate you from God’s love in Christ (Rom 8:38–39). Christ will lose none of those the Father gives him (John 6:37–40).

The Subjective Foundation: What the Spirit Confirms

The objective work of Christ alone isn’t enough for assurance; you need the Spirit’s witness. The Spirit himself testifies with your spirit that you are God’s children (Rom 8:16). When you believed, you were sealed with the promised Holy Spirit, who is a deposit guaranteeing your inheritance (Eph 1:13–14). John writes to believers so they may know they have eternal life (1 John 5:11–13)—certainty is possible now, not just hoped for later.

Assurance flows from union with Christ[1], and this involves what Calvin called the Spirit’s inner witness—direct and supernatural, though the Spirit can also use means like God’s Word to give assurance[2].

Your confidence rests on Christ’s finished work and the Spirit’s present confirmation. If you’ve genuinely believed in Jesus, you can know—not merely hope—that you belong to God and will spend eternity with him.

[1] Chun Tse, Assurance of Adoption: A New Paradigm for Assurance of Salvation (Eugene, OR: Wipf and Stock, 2020). [See here.]
[2] Michael A. G. Haykin, “Assurance,” in Dictionary of Christian Spirituality, ed. Glen G. Scorgie (Grand Rapids, MI: Zondervan, 2011), 281.