I take this quote to mean that I should not be indifferent to behaving as a Christian should. I should have strong affections towards holiness, obedience, and Christlikeness. If I don't, as my students would say. "It's time to check myself before I wreck myself."
If we are joined to Christ, our hearts will be no longer left under the power of sinful inclinations, or in a mere indifferency of inclination to good or evil; but they will be powerfully endowed with a power, bent and propensity to the practice of holiness,. By the Spirit of Christ dwelling in us, and inclining us to mind spiritual things and to lust against the flesh (Rom. 8:1, 4, 5; Gal. 5:17).
Let your current spiritual temperature be measured by a inclination-to-holiness-thermometer. And then cry for mercy and grace to press on.