The following blog post was originally published in May, 2017. —ed.

In the entryway to my parents’ home, there is what looks like a giant ruler bolted to the wall. It functions as a growth chart for their grandchildren, marking the incremental changes in their height through the years. And without fail, the kids are eager to see how much they’ve grown since their last measurement, delighted with their progress.

It is likely that somewhere in your childhood home—possibly near a doorframe—there are similar marks that measured your growth.

Whether it’s marking your height as a kid, or measuring your weight loss as an adult, it’s natural to want to quantify the progress you’re making. And it extends beyond just our physical condition. Many people fastidiously track their retirement accounts, their sleep habits, and even their gas mileage. If you can measure it, it’s certain that someone, somewhere is paying close attention to the numbers.

What if we could bring the same kind of scrutiny to our spiritual lives? Is there a reliable barometer of our spiritual growth—some way to track the trajectory of our sanctification? We put those questions to John MacArthur recently. Here’s what he had to say:

As John explained, spiritual growth is not measured incrementally, over short periods of time. Just consider the volatility of today alone—you might have begun your day in devotion and praise for the Lord, but it likely didn’t take long for you to succumb to temptation and sin.

Rather than tracking those lurching highs and lows, we need to consider the overall trend of our lives. Are we sinning less over time? Are we breaking old habits and gaining victory over sin in areas of life that were once dominated by defeat? And are we growing in our appreciation for just how sinful we are? Is the Spirit revealing new areas of sin in our lives, and are we attacking that sin biblically? If you want to get a sense of how you’re growing spiritually, you need to start with those questions.

At the same time, we need to remember that spiritual growth does not happen by osmosis. We can’t expect to grow if we’re not faithfully returning to the only true source of spiritual nourishment: God’s Word. And as John will explain next time, feeding on Scripture means a lot more than simply reading it.