Assurance from God’s Promises
A Christian’s assurance of faith is one of the strongest graces to energize godliness and zeal and one of the first fruits to suffer decline due to low levels of holiness and obedience. Well-cultivated assurance produces holy living marked by spiritual peace, humble gratitude, cheerful obedience, tenderness of conscience, freedom in prayer, boldness in evangelism, and heartfelt mortification of sin.
Therefore, it is of utmost importance for Christians to cultivate assurance of faith. The Westminster Confession (18.2) explains that assurance is founded upon God’s objective, unchanging promises of salvation; the inward evidences of Christian graces; and “the testimony of the Spirit of adoption witnessing with our spirits that we are the children of God.” Of these three foundations of assurance, the Puritan Anthony Burgess rightly says that it “is a more noble and excellent way” to find assurance of faith by relying upon God’s promise in Christ outside of us than it is to find assurance by being assured of the evidences of grace within us. In this article, therefore, we will consider the primary, objective ground of assurance: God’s promises of salvation. This emphasis on God’s promises in Christ implies several things for our experience of assurance.
God’s Faithful, Trustworthy Character
First, we gain assurance by looking to God’s faithfulness in Christ as He is revealed in the promises of the gospel rather than by looking at ourselves or anything we have produced. Our assurance is anchored in the character of our faithful God, who manifests Himself in the unchangeable person and finished work of His Son. God doesn’t speak out of both sides of His mouth. God’s Word is always trustworthy, and Jesus Christ is God’s everlasting “yea” and “amen” (2 Cor. 1:18–20). Thus, believers in Christ are assured of salvation because their God and their salvation are true, sure, perfect, and unchangeable in Jesus Christ forever. Believers in Christ are assured of salvation because their God and their salvation are true, sure, perfect, and unchangeable in Jesus Christ forever. Click To Tweet
Our salvation and security in Christ, therefore, rest on the immutability of God Himself (Mal. 3:6); the eternality of God’s electing love (Jer. 31:3); the irrevocability of God’s gifts (Rom. 11:29; cf. 1 Cor. 2:12); the inviolability of God’s oath (Heb. 6:17–20); the perfection of Christ’s work as Mediator (Heb. 10:19–23); and the sovereignty of the Spirit’s application of that work (1 Cor. 2:10–14).
In summary, if you are a believer, don’t doubt, but seek grace to enjoy the assurance that God has settled your account forever because He is satisfied with Christ for you as He is for every one of His repenting, believing people.
Growing in our Experience of God’s Promises
Second, as our assurance grows, God’s promises become increasingly real to us personally and experientially. The promises of God and assurance of faith reinforce each other. When God spiritually applies His promises to our hearts, He gives us, as Jonathan Edwards writes, “a spiritual sense or relish of the holy and divine blessings offered, and also the sweet and wonderful grace of the offerer, in making so gracious an offer, and of his holy excellency and faithfulness to fulfill what he offers, and his glorious sufficiency for it.”
As our experiential knowledge of God’s promises grows, then the more our hearts echo the truth of God’s promises. William Spurstowe (c. 1605–1666) said that God’s gospel promises are like stars at night. When you look into a dark countryside sky, you see few stars at first, but the longer you gaze into the sky and your eyes adjust to the night light, the more stars you see, until “the whole firmament, from every quarter, with a numberless multitude of stars, is richly enammelled as with so many golden studs.” So when we begin to meditate on God’s promises, the number of promises and the light coming from them may at first seem to be small and weak, so as to be insufficient to quell our fears and dispel our darkness, but when we read and meditate further—and begin to see the thousands of promises in the Scripture together with the bright light that shines from them clearly and distinctly—our souls are then ravished and filled with delight and assurance.
Glorifying God by Trusting His Promises despite Our Feelings
Finally, though subjective phenomena may sometimes feel more real than faith in God’s promises, such experiences give less glory to God than divine promises apprehended directly by faith. Burgess said, “Trusting in God and in Christ when we feel nothing but guilt and destruction in ourselves is the greatest honor we can give to God.” Thomas Brooks said that “the sight of Christ should be ten thousand times more comfortable and delightful” to us than the sight of our own graces.Finally, though subjective phenomena may sometimes feel more real than faith in God's promises, such experiences give less glory to God than divine promises apprehended directly by faith. Click To Tweet
Moreover, the smallest degree of saving faith in God’s promises will prove as effectual as full assurance of faith in God’s promises. The strength of a rock is constant, whether a spider’s web or an anchor is attached to it. The Lord Jesus Christ is just as much the rock of salvation for that trembling soul who grasps Him with a weak faith as He is for one who has full assurance of faith. Don’t’ forget that, as Brooks wrote, “The least degree of grace, if true, is sufficient to salvation.”
When Christian was confined in Doubting Castle in Pilgrim’s Progress, Giant Despair beat him and threatened to kill him the next day. But that night Christian remembered he had “the key of promise” in his pocket. Using that key, he quickly opened all the castle’s locks and escaped. Bunyan’s message is unmistakable: we don’t need an extraordinary personal revelation to believe that those promises are given to us.
But you may ask, how do I know I am truly living out of God’s promises in Christ and may draw assurance of faith from them? Thomas Brooks offered several ways we can know whether we have properly embraced God’s objective promises in Christ. By the Spirit’s grace, they include:
- resting my soul upon God’s promises, appropriating those promises to myself;
- subjecting myself gratefully to God’s words of command;
- waiting on God for the fulfilling of His promises in the face of discouragements and difficulties;
- having within me those divine graces to which these promises are made, such as faith, repentance, love, fear, hope, and patience;
- being united and married to Christ by faith;
- flying to God’s precious promises in my greats trials; and
- valuing God’s promises more than anything in this world.
Our conviction and feelings are fallible, but the objective promise embraced by faith is infallible because it is God’s comprehensive and faithful covenant promise. When we fear that since our heart is desperately wicked and that therefore we may be deceiving ourselves when we think we are trusting God’s promises, we must remember that in His Word, God pours His promises in Jesus Christ at our feet, and grants poor sinners like us freely to use them. As we believe in Jesus Christ who is the content of these promises, we discover to our astonishment and joy that Giant Despair is powerless to keep us as his prisoner. The gospel promises of God in Christ are mightier than all the arsenals of Satan and his minions.
 John Owen, Of the Mortification of Sin, in The Works of John Owen (1689; repr., Edinburgh: Banner of Truth, 1968), 6:33–53.
 Anthony Burgess, Faith Seeking Assurance, ed. Joel R. Beeke, Puritan Treasures for Today (Grand Rapids: Reformation Heritage Books), 140 (Spiritual Refining, 51).
 For a fuller treatment of most of these points, see Michael Barrett, Complete in Him (Grand Rapids: Reformation Heritage Books, 2017), 252–62.
 The Works of Jonathan Edwards (New Haven, Conn.: Yale University Press, 1959), 2:225.
 William Spurstowe, The Wells of Salvation Opened: or, A Treatise discerning the nature, preciousness, and usefulness of the Gospel Promises and Rules for the Right Application of Them (London: T.R. & E.M. for Ralph Smith, 1655), 78–79.
 Spurstowe, The Wells of Salvation Opened, 79.
 Burgess, Faith Seeking Assurance, 156 (Spiritual Refining, 57).
 Thomas Brooks, “A Cabinet of Jewels,” in The Works of Thomas Brooks, ed. A. Grosart (1864; reprint, Edinburgh: Banner of Truth, 1980), 3:502.
 Brooks, Works, 3:259.