I’ve been doing a lot of reading in Philippians lately and am quite interested in seeing how various scholars summarize the letter’s main purpose. I am particularly sympathetic to the views of those who explicitly factor in Paul’s repeated reference to φρόνησις (cf. φρονέω, 10x) and other kinds of cognition language.
For example, Wayne Meeks famously remarks, “[T]his letter’s most comprehensive purpose is the shaping of a Christian phrōnesis, a practical moral reasoning that is ‘conformed to [Christ’s] death’ in hope of his resurrection.”
I really like Stephen Fowl’s summary: “Paul is trying to form in the Philippians the intellectual and moral abilities to be able to deploy their knowledge of the gospel in the concrete situations in which they find themselves, so that they will be able to live faithfully.”
Here is my own summary, which is probably quite close to Fowl: “Paul seeks to show the church how to perceive, assess, and respond to its circumstances ‘in a manner worthy of the gospel of Christ’ (1.27)—namely, in a way that rightly grasps and appropriates the gospel’s eschatological trajectory, missional priority, and cruciform morality.”
 Wayne A. Meeks, “The Man from Heaven in Paul’s Letter to the Philippians,” in The Future of Early Christianity: Essays in Honor of Helmut Koester (Birger Pearson; Minneapolis: Fortress, 1991), 329-36, at 333.
 Stephen E. Fowl, “Christology and Ethics in Philippians 2:5-11,” in Where Christology Began: Essays on Philippians 2 (R. P. Martin and B. J. Dodd; Louisville: Westminster John Knox, 1998), 140-53, at 145. See also Lee S. Bond, “Renewing the Mind: Paul’s Theological and Ethical Use of Phronēma and Cognates in Romans and Philippians” (Ph.D.,
Univ. of Aberdeen, 2005).