That Christ serves for us as a paradigm for Christian life is not, as some fear, a betrayal of Paul's gospel. On the contrary, it reinforces a significant aspect of his gospel, namely that there is no genuine life in Christ that is not at the same time, by the power of the Holy Spirit, being regularly transformed into the likeness of Christ. A gospel of grace, which omits obedience, is not Pauline in any sense; obedience, after all, is precisely the point made in the application that follows (v. 12). To be sure, the indicative must precede the imperative, or all is lost; but it does not eliminate the imperative, or all is likewise lost.
Gordon Fee Paul's Letter to the Philippians (NICNT), p. 272.That last line is utter brilliance! Holding the indicatives of what God has done for us in Christ Jesus and the imperatives of obedience--holding these in the proper relationship is crucial. Fee, in one line, nicely captures some of the important relationship between them.