The Grounds of True Assurance (Chapter 18, Paragraph 2)

“This certainty is not a bare conjectural and probable persuasion grounded upon a fallible hope…”

The confession begins by distinguishing true assurance from mere speculation. Many in the world have a "hope" of heaven that rests on shifting ground: their own goodness, upbringing, church attendance, or feelings. But these are “fallible”—that is, unreliable. True assurance must not be confused with human optimism or sentimentality.

“…but an infallible assurance of faith…”

True assurance is rooted in saving faith itself, not in emotion or imagination. Faith rests on God’s promises, which are unchanging. Hebrews 6:18–19 calls these promises “a sure and steadfast anchor of the soul.” This assurance is infallible not because the believer is flawless, but because the object of faith—God’s Word—is perfectly trustworthy.

“…founded on the blood and righteousness of Christ revealed in the Gospel…”

Here is the solid ground: the atoning death and perfect righteousness of Jesus Christ. Assurance is not grounded in our performance, but in Christ’s finished work. The Gospel declares that sinners are justified by grace through faith in Him. The believer looks not to their works, but to the cross. Romans 8:1 affirms, “There is therefore now no condemnation for those who are in Christ Jesus.”

“…and also upon the inward evidence of those graces of the Spirit unto which promises are made…”

While the objective work of Christ is foundational, assurance is also supported by subjective evidence—the fruit of the Spirit within. 2 Peter 1:10 urges us to “make your calling and election sure” by confirming the presence of godly character: faith, virtue, knowledge, self-control, etc. The Spirit’s work is visible in a changed life. Love for God, repentance from sin, and growth in holiness are not the root of salvation, but they are its fruit—and they strengthen assurance.

“…and on the testimony of the Spirit of adoption…”

Romans 8:16 says, “The Spirit himself bears witness with our spirit that we are children of God.” This is not mere feeling—it is the Spirit applying the truth of Scripture to the believer’s heart. He convinces us that we belong to Christ. This inner witness assures the trembling saint that he is no longer a slave but a son.

“…witnessing with our spirits that we are the children of God…”

This internal witness is not vague or mystical but united with the Word of God. The Spirit assures the believer as they hear the Gospel, confess sin, and cry out in prayer. He assures us not apart from the means of grace but through them. When a believer, weighed down with sin, cries “Abba, Father,” that cry is itself evidence of adoption.

“…and, as a fruit thereof, keeping the heart both humble and holy.”

True assurance never leads to arrogance or lawlessness. It humbles the soul, reminding us that salvation is entirely by grace. It also stirs holiness, because those who are confident of God’s love will want to please Him. 1 John 3:3 says, “Everyone who thus hopes in him purifies himself as he is pure.” Far from creating complacency, assurance drives deeper godliness.

Application for the Believer:

Are you seeking assurance of your salvation? Don’t begin by examining your emotions. Start by looking to Christ—His blood, His righteousness, His Gospel. Then examine your life for the evidences of grace. Do you hunger for God’s Word? Do you hate sin and love righteousness? Do you cry out to God as Father?

If so, those are not works of the flesh but fruits of the Spirit. Ask the Holy Spirit to confirm these things in your heart. Let His witness bear fruit in your soul. Keep using the means God has given—the Word, prayer, fellowship, and obedience—and assurance will grow.

True assurance humbles us and makes us holy. It leads us away from pride and into deeper dependence on Christ. Seek this grace earnestly, knowing it brings not only joy and peace but a stronger walk with God and a greater longing for His glory.