Be diligent in these matters; give yourself wholly to them, so that everyone may see your progress. - 1 Timothy 4:15
Humans love to measure progress. We etch the heights of our children into door-frames; we have progress reports at our jobs; we water our plants and show one another the new growths peaking up from the soil.
Spiritual progress should be measurable also, but it can be uncomfortable to examine. The enemy can use shame to halt us when we slip into comparison to others. But He who began the work in us is faithful and will carry us to completion. That's a promise we can definitely hold on to, especially in the darkness.