Jon Bloom serves as author, board chair, and co-founder of Desiring God. He is author of three books, Not by Sight Things Not Seen , and Don’t Follow Your Heart . He and his wife have five children and make their home in the Twin Cities.

Jon Bloom serves as author, board chair, and co-founder of Desiring God. He is author of three books, Not by Sight Things Not Seen , and Don’t Follow Your Heart . He and his wife have five children and make their home in the Twin Cities.

Am I truly a Christian?

Few questions cause more fearful trembling in believers, and few soul-shepherds are as helpful as John Newton (1725–1807) in explaining to trembling saints how God cultivates assurance in the Christian life.

God loves to give his children the gift of “the full assurance of faith” (Hebrews 10:22). It is a precious thing, a source of deep peace and consolation, and he wants us to have it.

But like most things in the Christian life, assurance is something that is cultivated and grows deeper and stronger over time. It is a gift that God gives to us, according to Newton, gradually through frequent testing.

Assurance grows by repeated conflict, by our repeated experimental proof of the Lord’s power and goodness to save; when we have been brought very low and helped, sorely wounded and healed, cast down and raised again, have given up all hope, and been suddenly snatched from danger, and placed in safety; and when these things have been repeated to us and in us a thousand times over, we begin to learn to trust simply to the word and power of God, beyond and against appearances: and this trust, when habitual and strong, bears the name of assurance; for even assurance has degrees. (Newton on the Christian Life, 220)

In other words, God’s way of growing the sweet gift of assurance in us is by putting us through numerous and varied hardships. The process is designed to be hard. Trials are the way that faith is proven, refined, and strengthened. This is why James writes, “Count it all joy, my brothers, when you meet trials of various kinds, for you know that the testing of your faith produces steadfastness” (James 1:2–3).

Assurance Grows Through Spiritual Conflict

It’s why Paul writes, “We rejoice in our sufferings, knowing that suffering produces endurance [same word translated as “steadfastness” in James], and endurance produces character, and character produces hope” (Romans 5:3–4).

And it’s why the author of Hebrews reminds us,

It is for discipline that you have to endure. God is treating you as sons. For what son is there whom his father does not discipline? If you are left without discipline, in which all have participated, then you are illegitimate children and not sons. (Hebrews 12:7–8)

The discipline of enduring trials and sufferings ends up proving that we are God’s children. And though “for the moment all discipline seems painful rather than pleasant . . . later it yields the peaceful fruit of righteousness to those who have been trained by it” (Hebrews 12:11).

One of the peaceful, consoling fruits of the “righteousness of God that depends on faith” (Philippians 3:9) is assurance. And it’s a fruit that is realized “later” and in increasing amounts.

Why God Grows Assurance This Way

Why has God designed the process of giving us a growing assurance of faith through enduring trials? Newton answers this way:

We cannot be safely trusted with assurance till we have that knowledge of the evil and deceitfulness of our hearts, which can be acquired only by painful, repeated experience. (222)

Like Peter who confidently promised Jesus that he would never deny him only hours before he did, we do not realize as younger believers how powerful our sin nature is and how weak our faith is. We don’t know how proud and self-reliant we are. It is the fiery trials that apply heat to our faith and cause the dross of unbelief in the form of doubt, fear, anxiety, anger, jealousy, bitterness, selfish ambition, fear of man, and more to rise to the surface. And when we see the dross, we can fear that our faith may not be real.

And that’s what God wants. For when we see the horrible sin in us and feel our helplessness to get rid of it on our own, it pushes us in desperation to trust Christ’s work on the cross alone. When we see our numerous weaknesses and feel our helplessness to be strong on our own, it pushes us to search out and trust Christ’s promises to us alone.

We can have no security from gifts, labors, services, or past experiences; but that from first to last our only safety is in the power, compassion, and faithfulness of our great Redeemer. (234)

It is the various kinds of pressing, painful, exposing trials that teach us to trust in Christ for everything — to really “live by faith in the Son of God” (Galatians 2:20).

And so God grows the full assurance of faith in us and causes the joyful, peaceful fruit of righteousness to grow in us through trials. He wants our faith to rest fully on the Rock of Christ, so that we “rely not on ourselves but on God who raises the dead” (2 Corinthians 1:9). Because, as Newton said,

“We are never more safe, never have more reason to expect the Lord’s help, than when we are most sensible that we can do nothing without him.” This is the paradox of assurance. (234)

Through Many Dangers, Toils, and Snares

Newton spoke of assurance from experience. He said,

In mercy [God] has frequently stirred up my nest, shaken me in it, and forced me to fly to him, when I should otherwise have dropped into sleep and [false] security. (221)

For Pastor Newton, the sweet God-given gift of assurance looked much like verse three of his famous hymn, “Amazing Grace”:

Through many dangers, toils, and snares I have already come; His grace has brought me safe thus far, And grace will lead me home.

Our assurance of salvation does not come from a confidence in some subjectively measured inner witness, nor how warm our affections for God are at any given moment. Rather, our assurance comes from a growing confidence in Christ’s saving work that purchased the fulfillment of all his great promises to us (2 Peter 1:4) and his power to keep them.

Greater assurance comes through stronger faith. And faith only grows stronger through the vigorous exercise of testing.