In our proper desire to see Christians grow in sanctity (holiness) Christians have often succombed to the temptation to encourage sanctity by making justification or deliverance from the judgment to come contingent upon our degree of sanctity. The great difficulty with this scheme, apart from the fact that it is unbiblical, is that it doesn’t work. It has never worked. As a scheme for promoting sanctity it is unworthy of the gospel, which is not an announcement of the potential of justification or even of the possibility of salvation for those who do their part. No, the gospel is an announcement that God has saved his people—”I am the Lord your God who brought you out of Egypt, out of the house of slavery”—and is saving his people now. We, believers, are striving toward sanctity, we are obeying by grace alone, through faith alone in Christ alone because we’ve been delivered, because “there is therefore now no condemnation for those who are in Christ Jesus” (Rom 8:1). Paul did not say that there might be condemnation if we do not make sufficient progress in sanctification. Yes, Hebrews 12:14 says, “Strive for peace with everyone, and for the holiness without which no one will see the Lord” (ESV) but we’re not entitled to turn that statement of fact into a condition as if the pastor was telling those tempted to go back to Moses that God will accept them if and when they achieve sufficient progressive sanctification. No, this verse is part of an exhortation that is grounded in the gospel. It begins, in v. 1, with a “therefore.” We’re surrounded with a great cloud of witnesses. Jesus is the author and perfecter of our faith. He did not despise the shame of the cross and neither should we Christians. In union and communion with the risen Christ, who was shamed for us, we should accept the taunts and humiliation (and not turn back to the old covenant) that accompany the Christian confession. God is sanctifying us through these trials. “Therefore” (v. 12) we ought to lift our “drooping hands” (ESV) and strengthen our weak knees (tempted to turn backwards) and go forward in holiness. It is the holy who will see God. We’ve come to an even greater mountain than the mountain on which Moses stood. We’ve come to the heaven Zion, where Christ is at the top of the mountain and he dwells in holiness. This how things are.
Paul says essentially the same thing in Philippians 1:
Only let your manner of life be worthy of the gospel of Christ, so that whether I come and see you or am absent, I may hear of you that you are standing firm in one spirit, with one mind striving side by side for the faith of the gospel (Phil 1:27; ESV)
Since we have been justified, since we have been delivered and are being delivered from the judgment to come by God’s sovereign, unconditional grace, through faith alone, in Christ alone we ought to conduct ourselves in a certain way—not in order to gain acceptance with God but in light of what Christ has done for us (incarnation, substitutionary obedience and death, resurrection, and ascension) and in communion with the living Christ who is working in us by his Spirit.
What does it mean to walk, i.e., to conduct ourselves worthy of the Good News? It’s as much an attitude, a way of thinking, as a list. Of course it means to reckon ourselves dead to sin and alive to Christ. Of course it means to look to God’s holy law as the norm for our lives in Christ. Specifically he exhorted the Philippian Christians to “stand firm,” and to agree (a major theme in Philippians), and to “strive side by side for the gospel” (ESV). It meant that they needed to stand up to the opponents of the gospel (Judaizers; v. 28) and that they needed to be prepared to suffer for Christ’s sake (v. 29).
Were someone to give us a gift of great value how should we respond? We wouldn’t spit in the eye of the donor. We would receive the gift thankfully. We take good care of the gift. We live appropriately, as those who’ve been given a great gift, because we have been given a gift of unspeakable value.
This is Paul’s consistent way of thinking and speaking about the motivation behind the Christian life. This is what the Reformed meant to say when they spoke of gratitude. They weren’t thinking only of an attitude but of a way of life growing stemming from and living in God’s grace. When Paul says “worthy of the gospel” he doesn’t mean “in order that we might benefit” but because of the gospel, in light of the gospel, as one who has already received (and is receiving) the benefits of the gospel: justification and sanctification.