Every seasoned Christian knows the pain: we’ve followed Jesus for years, and yet we’re nowhere near like Him.

Sure, we’ve made progress. We’re not the people we used to be, but let’s be honest, we’re still not quite the people we WANT to be. He has been chipping away at us—one painful, stubborn sin at a time. Yet the question lingers, “If God’s all-powerful and loves me, why’s this taking ever so long?”

It’s a fair question, especially considering what God already did for us at conversion. He justified us—declared us righteous in His sight—in an instant. The moment we believed, our legal standing before God changed completely. So why doesn’t He finish the job just as quickly?

 

WHEN GOD WORKS IN A MOMENT VS. WHEN HE WORKS OVER A LIFETIME

To understand the answer, we need to distinguish between two different works God does in every believer: justification and sanctification.

Justification is God’s legal declaration. It’s akin to the courtroom scene where the Judge bangs His gavel and pronounces us “not guilty.” This happens because Christ’s perfect righteousness is credited to our account. As Paul writes, we are “justified by his grace as a gift” (Romans 3:24). This is instantaneous—a done deal the moment we trust Christ. Our status before God changes in a heartbeat, once and for all.

Sanctification is something different entirely. This is the gradual, often frustrating process of actually becoming holy in our daily life—not just being declared holy in heaven’s courtroom. It’s the Spirit’s work of transforming our character, our habits, our reflexes—even our desires—so we become more like Jesus. Paul captures this when he tells the Philippians to “work out your own salvation with fear and trembling” (Philippians 2:12). Notice: not work for salvation, but work out what God is working in.

So why does God instantly justify but slowly sanctify?

 

WHY SANCTIFICATION MATTERS SO MUCH

Before we ask why sanctification takes time, we need to understand why it’s necessary at all. The answer is sobering: God is preparing us to live in His presence forever, and His holiness isn’t something sinful creatures can casually approach.

Throughout Scripture, God’s holiness is portrayed as blazing, consuming, dangerous to anything impure. When Isaiah saw the Lord in His temple, he cried out, “Woe is me! For I am lost; for I am a man of unclean lips” (Isaiah 6:5). When God descended on Mount Sinai, the people had to keep their distance or die (Exodus 19:12-13). The writer of Hebrews reminds us “our God is a consuming fire” (Hebrews 12:29).

Here’s the reality: justification makes us legally acceptable to God, but sanctification makes us actually fit for intimate fellowship with Him. Hebrews is crystal clear: “Strive…for the holiness without which no one will see the Lord” (Hebrews 12:14). God hasn’t stopped being holy. Heaven isn’t a place where sin is tolerated—it’s a place where sin cannot exist.

If God brought us into His unshielded presence with our current level of remaining sin, His holiness would destroy us. Sanctification isn’t God’s hobby project—it’s His rescue mission, gradually conforming us to the image of His Son so that one day we can stand in the full blaze of His glory and experience it as pure joy rather than as an all-consuming judgement.

 

FOUR REASONS GOD TAKES HIS TIME

We’re Human, and We Learn Slowly: God designed us as creatures of time, habit, and process. We didn’t develop our personality, our fears, or our sinful patterns overnight—why would changing them happen any faster?

Paul speaks of the “renewing of your mind” (Romans 12:2), which inherently takes time. Our brain needs repeated experiences to form new neural pathways. Our heart needs consistent practice to develop new reflexes. The writer of Hebrews explains maturity comes to “those who have their powers of discernment trained by constant practice” (Hebrews 5:14). Notice that word: constant. Sanctification respects the way God actually made us to grow.

God Uses Ordinary Means, Not Magic Wands: God could zap us into perfection, but that’s not His usual way. He works through Scripture reading, prayer, Christian community, and yes, even trials and failures. Peter describes this incremental approach: “Make every effort to supplement your faith with virtue, and virtue with knowledge, and knowledge with self-control…” (2 Peter 1:5-6). One virtue builds on another.

James adds trials produce endurance, and endurance produces maturity (James 1:2-4). The struggle itself is formative. If God instantly perfected us, we’d miss the classroom where the deepest lessons are learned.

The Long Road Keeps Us Dependent: Here’s an uncomfortable truth: if we were to think God has sanctified us completely, we’d probably become insufferable and proud. But ongoing struggle? That keeps us humble.

Paul learned this when God refused to remove his “thorn in the flesh.” God’s response? “My grace is sufficient for you, for my power is made perfect in weakness” (2 Corinthians 12:9). The apostle’s weakness kept him clinging to Christ. Our weakness does the same. Every time we fail and return to God for mercy, we’re learning what we most need to know: we’re completely dependent on grace.

Gradual Transformation Displays Greater Glory: Think about it: which brings greater glory—instantly creating a finished product, or patiently, lovingly transforming broken material over a lifetime? Our sanctification is a slow-motion miracle that puts God’s patience, faithfulness, and transforming grace on display for the world to see.

Paul promises that “in the coming ages” God will showcase “the immeasurable riches of his grace in kindness toward us” (Ephesians 2:7). Our story of gradual change, with all its setbacks and returns to grace, tells a richer tale than instant perfection ever could.

 

COMFORT IN THE STRUGGLE

Here’s the good news: sanctification’s slowness isn’t evidence that God has given up on us—it’s evidence something’s indeed working in us. The fact that we’re fighting sin means we’re spiritually alive, not spiritually deficient.

And God, in His wisdom, doesn’t overwhelm us with the full weight of our sinfulness all at once. God knows our capacity. He works with us at our pace, addressing one area of sin at a time. Layer by layer, like a skilled surgeon who wouldn’t attempt every necessary procedure in a single operation. If He showed us everything that needs changing simultaneously, we’d be crushed under the weight. Instead, He gently points to one thing, then another, patiently working through the list over a lifetime.

And our progress doesn’t depend on our willpower. Paul assures us “He who began a good work in you will bring it to completion” (Philippians 1:6). God finishes what He starts. The same God who justified us in a moment will glorify us completely—just not yet.

Until then, let’s embrace the long road. God’s taking His time because the journey itself is part of His grace.

 

LONG ROAD TO SANCTIFICATION: RELATED FAQs

If sanctification is God’s work, why does it require such violent effort on our part? John Piper famously speaks of the “violence” required in fighting sin—cutting off hands, gouging out eyes (metaphorically, of course). Yet Reformed theology insists God alone sanctifies us (monergism). How do these fit together? The answer is that God works through our effort, not instead of it. As Jonathan Edwards explained, God’s sovereignty doesn’t make our actions unnecessary—it makes them certain. When God sanctifies us, He does so by giving us the will and power to fight (Philippians 2:13). Our striving is real, but it’s God-enabled striving. We’re not contributing independent power; we’re actively cooperating with the power He supplies.

• Did the Puritans have a different view of how long sanctification takes? The Puritans were intensely focused on progressive sanctification and spoke often of the “mortification” (killing) of sin as lifelong work. John Owen warned “be killing sin or it will be killing you,” emphasising the daily, ongoing battle. They saw sanctification as involving both crisis moments and gradual growth, but never expected perfection in this life. Thomas Watson wrote, “A saint is never perfect until he is in paradise.” Their realism about sin’s tenacity, combined with confidence in God’s grace, deeply shaped Reformed spirituality.
• Does everyone progress in sanctification at the same pace? Scripture and experience both suggest varying rates of growth among believers. Some sins yield quickly; others are lifetime battles. Some Christians seem to mature rapidly; others struggle for decades with the same issues. What Reformed theology affirms is that *all* genuine believers will show *some* progress (1 John 3:9), but the rate and pattern vary according to God’s sovereign purposes, individual temperament, past wounds, and external circumstances. The promise isn’t uniform speed—it’s certain completion.
• What did Calvin say about the relationship between justification and sanctification? Calvin held justification and sanctification in careful balance, calling them “inseparable” yet “distinct.” In his Institutes, he wrote they’re like “two distinct graces” that “are never disjoined.” He argued against Rome’s view that merged them, and against antinomianism that separated them. For Calvin, both flow from union with Christ: justification addresses our legal guilt, sanctification our moral corruption. You cannot have one without the other because both come from being joined to Christ, but they remain distinguishable in their nature and timing.

How should we respond when we we’re making no progress at all? First, let’s remember spiritual perception is often distorted—increased awareness of sin can actually indicate growth in holiness, not regression. The closer we get to the light, the more we see what needs cleaning. Second, let’s look for fruit in unexpected places: perhaps our patience has grown even if our pride hasn’t budged. Third, let’s remember perseverance itself is evidence of grace—the fact that we haven’t given up proves God is holding is (John 10:28-29). Finally, let’s revisit the promises: God who began the work will complete it, regardless of how we feel today (Philippians 1:6).

 

LONG ROAD TO SANCTIFICATION: OUR RELATED POSTS

• The Christian Heart: Is It Still ‘Desperately Wicked’?
• Battling Recurring Sin: What Sanctification Looks Like in Real Life
• Can Repentance be Real If We Struggle With Habitual Sin?
• When God Gives Us A New Heart: How Grace Rewires Our Desires
• Saints and Sinners: Why Does the Bible Use Both Terms for Christians?