I learned recently that many of the epistles have a main theological point. For example, the main point of Ephesians is that the Church is the body of Christ, and that it may bring unity to the world and reconciliation with God. The main point of Colossians is the supremacy of Christ, as he existed before creation. These points can be verified by reading the epistles, or, more briefly, by reading the linked articles on Wikipedia.
This leads me to wonder, what is the main theological point of Philippians? In other words, what is the main theme, from a theological perspective, if there is one?