Not that I have already obtained this or am already perfect, but I press on to make it my own, because Christ Jesus has made me his own. Brothers, I do not consider that I have made it my own. But one thing I do: forgetting what lies behind and straining forward to what lies ahead, I press on toward the goal for the prize of the upward call of God in Christ Jesus. Let those of us who are mature think this way, and if in anything you think otherwise, God will reveal that also to you. Only let us hold true to what we have attained.The beginning of this passage affirms that what has been attained was not by Paul's causal effort but Jesus's causal effort. And the passage ends with Paul saying, "Let's hold to what we've already got."
-- Philippians 3:12-16
"Not that I have already made it my own; Jesus has made me his own."
"Only let us hold true to what we have attained."
We don't graduate from the gospel. We hold true to it. And it alone propels us out and empowers us to press on. Grace-driven effort flows from the joys and wonders of worship that flow from beholding the amazing gospel of God's grace.
Were this true in you, the sin in you would become your enemy. Do you profess Christ? Have you received Christ? Then, "Don't just avoid sin; hate it" (Ed Welch). Be as intentional with your sin as Christ was. Carrying the banner of the gospel, which declares Christ's conquering of sin and death, make bloodthirsty war with the sin in you. Watch for it, search it out, assassinate it with the word of God. Arm yourself with Spiritual armor, put on Christ, and spare no sin you find. Kill it, even as you trust the Spirit is killing it on your behalf. Because he is. And if he is, you should be too.
You won't drift into holiness. The Spirit will take you there. But God uses means to achieve his ends, and his earthly means of Spiritually sanctifying you is your pursuit of the righteousness of Christ. That we are "being transformed" is a promise; that we should "be transformed" is a command (2 Cor. 3:18; Rom. 12:2). This Spiritual tension causes Walter Marshall to affirm in The Gospel Mystery of Sanctification, his classic work affirming that grace is not only the grounds of our justification but our sanctification as well, that the reader must "endeavour diligently to make right use of all means appointed in the word of God, for the obtaining and practising holiness."
This is an excerpt from my book Gospel Wakefulness (pp. 140-141).