SANCTIFICATION AS SPIRITUAL FITNESS: Strengthen Your Soul for Life’s Journey

Imagine how different life would be if, as we age, we could continue to become more

physically fit. Of course, physical strength naturally declines over time, no matter how disciplined we are. But spiritual fitness follows a different trajectory—it can keep increasing throughout our lives! That’s the beautiful reality behind the Christian doctrine of sanctification.

A Lifelong Process of Growth

“Sanctification” is the term Bible scholars use to describe the process by which God transforms us into the image of Christ. When we place our faith in Jesus, God's work in us begins, not ends. From that moment on, He sets about conforming us to the likeness of His Son.

But this process isn’t automatic. Just as physical training takes commitment and effort, sanctification requires our cooperation. God’s will is for us to be sanctified (1 Thessalonians 4:3), and that means becoming holier, more Christlike, and more spiritually mature over time.

Hebrews 12:14 calls us to “make every effort to be holy.” Spiritual fitness doesn’t happen overnight. Like physical strength, it grows gradually, sometimes unevenly, through daily effort and God’s ongoing grace. Even when we face setbacks, we can trust that God is renewing us day by day (2 Corinthians 4:16) and transforming us from glory to glory (2 Corinthians 3:18).

Spiritual Fitness Is Holistic

Whereas physical fitness often targets individual muscle groups or specific health goals, spiritual fitness is holistic. It touches every aspect of our lives—our thoughts, emotions, behaviors, and relationships. Romans 12:1 tells us to offer our whole selves as living sacrifices, holy and pleasing to God.

That means sanctification affects everything: our family life, friendships, work habits, hobbies—even how we think and speak. As Abraham Kuyper said, there’s no square inch of our lives over which Christ does not declare, “Mine!” True spiritual fitness shows up not just in our quiet times or church attendance but in how we live every day.

Just as athletes break bad habits and adopt disciplined routines, so too must we shed sinful patterns and cultivate Christlike practices. Over time, these habits reshape every domain of life—spiritual, emotional, creative, vocational. Sanctification transforms us from the inside out.

The Holy Spirit: Our Spiritual Trainer

No one gets physically fi t without help, and the same is true spiritually. We cannot become holy in our own strength. The Holy Spirit is our guide, our encourager, and our power source. He enables us to do what our sinful nature never could (Romans 8:3-4).

At conversion, the Spirit baptizes us into the body of Christ (1 Corinthians 12:13), dwells within us (1 Corinthians 6:19-20), and empowers us with spiritual gifts (Romans 12:3–8). He’s like a personal trainer— pointing us to truth, helping us resist sin, and growing us in love, wisdom, and courage.

The Holy Spirit doesn’t merely teach us about God; He draws us closer to God, enabling our transformation. And through His presence, we are sealed for the day of redemption (Ephesians 4:30).

A Fitness Plan That Pays Eternal Dividends

As we’ve seen, spiritual fitness can thrive even while our bodies weaken. The apostle Peter

encourages us to “grow in the grace and knowledge of our Lord and Savior Jesus Christ” (2 Peter 3:18). And while that growth is often hard-fought, requiring daily surrender, prayer, Scripture, and community, it’s also deeply rewarding.

Unlike physical fitness, which often brings short term results, spiritual fitness yields eternal rewards. It deepens our relationship with God, equips us to serve others, and prepares us for life in eternity.

So let’s not miss this calling. Let’s cooperate with God in His transforming work. There will be slow days and setbacks, but every step of growth reflects His grace and power at work in us.

Let us cast aside apathy and distraction. Let us grow strong in Christ, not just for our own sake but for the sake of those we’re called to love and serve. The goal is not perfection in this life, but progression—becoming more spiritually fit each day, until the day we see Jesus face to face.

Find help in sanctification and growing spiritually fit at backtothebible.org or get the GOtandem app in your favorite app store.