How can you know if you are making progress in your sanctification and how can you know how much progress you are making? Is sanctification something that can be measured?
Paul believed that sanctification has degrees. You can grow. He prays that “your love may abound more and more” (Phil. 1:9). He says the Thessalonians are pleasing God and tells them to “do so more and more” (1 Thess. 4:1). He tells the Corinthians that God will “increase the harvest of your righteousness” (2 Cor. 9:10). And prays, “May the Lord make you increase and abound in love for one another and for all” (1 Thess. 3:12).
But the New Testament does not quantify these degrees. “More and more” and “increasing” are discernible but not measurable. That is, while length is quantified in inches and feet. Holiness does not have similar measuring units.
So how do you know you are making progress? There is a paradox here. On the one hand, greater holiness is greater victory over sins. But on the other hand, greater holiness is greater sensitivity to and hatred for sin. So it does not follow that becoming more holy will mean becoming more happy with oneself. You may be a better person tomorrow and feel worse about the smaller corruption that remains.
But there are ways to discern growth. One is that those around you will see it and confirm it. Another is that you will see some of it. You will feel the weakening of some temptations as love for Christ pushes the desirability of sin far away. You will feel drawn to holy acts that once were burdens. And you will have holy sorrow when you omit them, not just guilt over a duty neglected. You will see the preferences in your life change. What was once supremely desirable is trumped by a superior desire for Christ and his word and his way. And you will confirm your heart change in action. Action that becomes less burdensome as love grows. “This is the love of God, that we keep his commandments. And his commandments are not burdensome” (1 John 5:3).
We can and should make progress in sanctification. And we can and should be aware that it is happening. This will encourage us that God is at work in our lives. And it will humble us because progress will mean we can see more clearly how far we have to go and how small are our advances. And how much we will always need a great Savior.