From reflection on the present, which is a cause for joy, Paul now turns to assess the future, which is also cause for joy. The passage comes in three parts, held together by the anticipation of his (apparently) soon-expected trial (vv. 19-20). Verses 19-20 offer the reason for his continuing joy—his earnest expectation that Christ will be magnified whatever the outcome (life [ released] or death [ executed]). Even though he has no real choice in the matter, in verses 21-24 he ponders the options of life and death. Paul's clear preference is death, since that means to gain the final prize—Christ himself (cf. 3:12-14). But he expects the outcome to be life—since that is what is best for the Philippians. Verses 25-26 then offer the end result of his being given life—your progress (cf. v. 12) and joy in the faith.
Although this reflection is far more personal than verses 12-18, even here the focus is still on Christ and the gospel. By a fresh supply of the Spirit of Jesus Christ Paul expects his hope to be fulfilled, that Christ will be exalted whether Paul lives or dies; for to live means Christ and to die means to gain Christ. If he had a choice, he would choose death, because that would mean to be with Christ; but since he has no choice, life is the expected outcome, leading to his return to Philippi and their overflow of joy in Christ Jesus.
Most likely all of this is for the Philippians' sakes as well. As Paul's present joy is expressed in the face of conflict (some believers in Rome against him), so with his future joy, which will find expression in the face of external opposition—a point that will hopefully not be lost on the Philippians. For reasons not known to us, some of them have apparently lost their grip on future certainties (see on 1:6). Hence even this personal musing functions as paradigm. The future—the full realization of Christ—is a glorious prospect, Paul reassures them, even if it were to mean in his case to arrive there prematurely at the hands of others!
Again we see the three-way bond—between him, them and Christ—that informs every part of the letter. The present emphasis is on Paul's relationship with Christ (to live is Christ; hence his desire is to be with Christ); it concludes on the note of his relationship with them (they will glory in Christ on account of him when he comes to be with them), which has their relationship with Christ as its ultimate concern (their progress and joy in the faith).
All told this is one of the apostle's finer moments, a passage to which God's people have turned over and again to find strength and encouragement in times of difficulty. We all are the richer for it.
IVP New Testament Commentaries are made available by the generosity of InterVarsity Press.