At John’s birth, Zechariah suddenly found himself prophesying of this coming Messiah and the purpose he would accomplish in and through the people He would save:
“That we, being delivered from the hand of our enemies, might serve [God] without fear, in holiness and righteousness before him all our days” (Luke 1:74-75)
We who are delivered from the world to be followers of Christ have the privilege and responsibility to serve God in holiness and righteousness, to be set apart for service to God by our conformity to God. This is why God plants within each of His people a deep loathing for sin and a great longing for godliness. The prayer of David should often be heard coming from our lips: “Let the words of my mouth and the meditation of my heart be acceptable in your sight, O LORD, my rock and my redeemer” (Psalm 19:14). We, too, should pray that all of us—our heart, our mouth, our inner man, and outer man—are marked by God and consecrated to God.
When we put our faith in Jesus Christ, we are immediately justified, declared righteous in the sight of God. Simultaneously, we receive the guarantee that we will eventually be glorified, that we will some day be perfected in the presence of God. But between the two lies the task of growing in conformity to Jesus Christ. Between justification and glorification—each accomplished in a moment—lies sanctification, which is accomplished in a lifetime.
This is a lifetime of relying on the Spirit, taking hold of His promises and power, and joining with Him in this great task.
This world is our training ground, in which we respond to justification and ready ourselves for glorification. We do this by putting off what we were and becoming what we are.
– Tim Challies