NOTE: This is a condensed excerpt from my forthcoming (2014) commentary on Philippians.
Paul’s desire for the Philippians’ love to increasingly abound in knowledge and discernment/insight indicates at least two things. First, although love must have some basis in basic knowledge, its depth, consistency and endurance in some sense depends on growing knowledge of the person or object loved. Knowledge is not the enemy of love for God, but a necessary condition for its existence. In a healthy marriage, a husband’s love for his wife (and vice versa) deepens as he grows in his knowledge of her. The same is true of our relationship with God; as we grow in our understanding of him and his ways, our love for him, his gospel, his people and the world will deepen as well. Second, the fact that Paul prays for this growth in knowledge and insight/discernment implies that it is God who must grant these realities. While it is our responsibility as believers to pursue growth in knowledge and discernment/insight through the available means such as the preaching of God’s Word, reading/studying the Bible and helpful Christian literature, these activities are insufficient in and of themselves to produce the kind of knowledge and discernment/insight Paul speaks of here. Apart from the supernatural work of God’s Spirit to use those efforts, the only kind of knowledge gained from those activities is the kind that makes a person arrogant (cf. 1 Cor 8:1). Bockmuehl summarizes the thought well here: “Christ, it seems, has no place for love that is selfish, indulgent, and lacking in discrimination—nor indeed for knowledge that does not express itself in love.” How essential it is then to pray that God will grant us knowledge and discernment/insight that works itself out in tangible acts of love for God and others.
 Bockmuehl, Philippians, 67.