Sanctification: How to Measure Spiritual Growth Over Time

Sanctification is the process by which God actually changes you – not just your standing before him, but your appetites, your reflexes, your loves. It isn’t a one-time event you can point to on a calendar, and it doesn’t happen automatically just because time passes. Scripture calls believers to examine themselves, which means sanctification is something you can actually track, if you’re willing to ask a few uncomfortable questions.

What Sanctification Really Means in Scripture

Sanctification means being set apart and made holy, and Scripture is careful to keep it distinct from justification. Justification happens in an instant – the moment you trust Christ, God declares you righteous, fully and finally, saved, and in His hands. Sanctification is different. It’s the ongoing work of the Holy Spirit conforming you to the image of Jesus, and it happens over the whole span of a believer’s life.

Paul says it plainly in Philippians: “And I am sure of this, that he who began a good work in you will bring it to completion at the day of Jesus Christ” (Philippians 1:6). God started the work. He isn’t finished with it, and neither are you.

Paul also names the goal in Romans – believers are predestined “to be conformed to the image of his Son” (Romans 8:29). That’s the target. Not moral improvement in general, but an increasing resemblance to Christ himself. Here’s how Paul describes what that looks like in motion.

And we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another. For this comes from the Lord who is the Spirit. [2 Corinthians 3:18]

Notice the phrase “from one degree of glory to another.” That’s not a light switch. That’s a gradient, a slope, a direction of travel. Sanctification is real, but it’s incremental – which is exactly why it can be evaluated.

A Process, Not a Single Moment

Sanctification unfolds over years, not overnight, and growth like that rarely shows up on any single day. The writer of Hebrews compares the Christian life to discipline for exactly this reason: “For the moment all discipline seems painful rather than pleasant, but later it yields the peaceful fruit of righteousness to those who have been trained by it” (Hebrews 12:11). Notice the word “later.” Training takes time to show results, and so does sanctification.

This is why the honest way to evaluate your own growth isn’t to compare yourself to yesterday. It’s to compare who you are now to who you were five or ten years ago. Zoom out far enough, and the trajectory becomes visible even when the day-to-day feels flat.

Questions That Reveal Whether You’re Actually Growing

If sanctification is real in your life, it leaves evidence. The following questions aren’t meant to produce guilt for its own sake – they’re meant to help you see where the Spirit has actually moved, and where he still has ground to take.

Do I Repent Quickly, or Defend Myself?

Growing believers repent faster than they used to, and they repent instead of defending themselves. Early on, conviction can sit for days before it changes behavior. And, the first instinct when confronted is almost always self-justification – “you don’t understand the pressure I was under,” or “well, they started it.” Real growth looks like that gap closing. Conviction lands sooner, and it’s followed by actual repentance rather than a rehearsed defense. John puts the alternative plainly: “If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness” (1 John 1:9). Proverbs adds the warning side of it: “Whoever conceals his transgressions will not prosper, but he who confesses and forsakes them will obtain mercy” (Proverbs 28:13). Ask yourself honestly which pattern describes you now compared to a few years back.

Am I Growing in Love for Difficult People, or Just Avoiding Them?

Real sanctification shows up in how you treat the coworker who talks over you in every meeting, or the relative who never lets an old grudge die. It’s easy to mistake distance for maturity. You stop engaging with a difficult person, the friction disappears, and it can feel like peace – but avoidance isn’t love, and it isn’t growth. The question worth asking is whether you’re actually more patient and more genuinely kind toward hard people, or whether you’ve simply gotten skilled at keeping them at arm’s length. Those are two very different outcomes, and only one of them is sanctification.

What Do I Increasingly Want When No One Is Watching?

What you crave in private tells you more about your sanctification than what you do in public ever will. Anyone can hold it together at church or in front of people who expect certain things from them. The real question is what you reach for when you’re alone with no audience at all – and whether what you teach or tell others to do is actually what you practice when it costs you something unseen. Peter describes a growing appetite in believers: “Like newborn infants, long for the pure spiritual milk, that by it you may grow up into salvation” (1 Peter 2:2). If that craving is increasing, something real is happening.

Is the Fruit of the Spirit Actually Growing in Me?

Paul gives a specific, checkable list, and it’s worth returning to often precisely because it’s so concrete.

But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law. [Galatians 5:22-23]

Here’s a useful test: if the people who know you best – a spouse, a longtime friend, someone who’s watched you closely for years – compared you to who you were several years ago, would they see more of this list, not less? And here’s the harder version of that same question: is your public spirituality bigger than your private devotion? A life that performs well on Sunday but starves the rest of the week isn’t sanctification. It’s management.

Do I Have More Grace for Other People’s Weaknesses?

Growth shows up as more grace toward others’ failures and less tolerance for your own. Jesus names the opposite pattern directly: “Why do you see the speck that is in your brother’s eye, but do not notice the log that is in your own eye?” (Matthew 7:3). A believer who’s maturing gets slower to condemn in someone else the exact sin they quietly excuse in themselves. If you find yourself harder on other people’s failures than your own, that’s not a small inconsistency – it’s a signal worth taking seriously.

Is Christ Becoming More Precious to Me, or Just More Familiar?

This might be the most important question of the six, because it gets at motive rather than behavior. Familiarity with Christ can grow while affection for him quietly shrinks – you know the routines, the language, the right answers, and none of it moves you the way it once did. The psalmist describes something different: “As a deer pants for flowing streams, so pants my soul for you, O God” (Psalm 42:1). That’s longing, not routine. Ask yourself plainly: does your schedule of spiritual habits satisfy you more than actually encountering Christ does? If the routine has become the point, something has gone quiet that shouldn’t have.

Where This Leaves Us

None of these questions are meant to leave you weighing your own salvation – sanctification is evidence of grace already at work, not a scoreboard you have to win. Paul’s prayer for the Thessalonians makes the promise plain: “Now may the God of peace himself sanctify you completely… He who calls you is faithful; he will surely do it” (1 Thessalonians 5:23-24). The work is His. Your part is simply to keep asking the honest questions and to keep letting him answer them.