In the last section, Paul mentioned that he prayed for the Philippians. In these verses we find out exactly what it is that he prayed for.
Abounding Love (9a): Just like the prayers of 1 and 2 Thessalonians, the prayer here is for an abounding love. Since the Philippians had already shown love toward others, Paul does not pray for the mere presence of this love but for its increase: "that your love may abound still more and more." This is very much like the exhortation to the Thessalonians "to excel still more" (1 Thess. 4:9-10). Certainly, we, too, can grow in our Christian love! And what Paul shows us here is that this love is not reached by effort alone but by the work of God. It is to be prayed for! We should ask God for our love to abound!
Smart Love (9b): Now, Paul prays that their love would grow in specific areas of "real knowledge" and "all discernment" (1:9). "Real knowledge" has to do with information or doctrine, and points to biblical knowledge of love. Some examples of this would be: sacrificial love vs. personal freedom, man's love for his wife, love with actions. The second area of growth is "all discernment." This speaks of a insight into each situation that discerns how to practically love someone. Paul points out that love should grow in "all discernment" so as to point out that this is comprehensive wisdom. This implies that love can always grow. Who can ever say that their love abounds with all discernment? Well, a love that abounds in knowledge and discernment is simply "smart love." God wants His people to exercise a love informed by biblical knowledge and exercised with wisdom that discerns the right time, the right actions, the right words, etc. Smart love isn't just passion or just compassion or just sacrifice. Smart love is biblical (what's best in God's eyes?) and insightful (what's best for each situation?).
Good Results (10-11): It goes without saying that smart love will lead to good decisions. This is the point of verse 10, "so that you may approve the things that are excellent." Smart love means better choices with our time, relationships, resources, words, etc. Beyond this immediate result, Paul names a few ultimate results. The first result is "to be sincere [as in pure] and blameless." This is a description about who we are as people: our character. As we strive to love smarter and make better decisions, we ourselves grow more acceptable in the sight of our Savior who is coming again. Paul then adds to this an agricultural metaphor (second result): "filled with the fruit of righteousness." As a fruit tree should be full of fruit, so our purpose in life is to be full of fruits of righteousness, sincerity and blamelessness, and smart love in the eyes of God. This is the way we can give God "glory and praise"!
 "always offering prayer with joy in my every prayer for you all" (1:4).
 Prayer: "may the Lord cause you to increase and abound in love for one another, and for all people" (1 Thess. 3:12). Answer to prayer: "your faith is greatly enlarged, and the love of each one of you toward one another grows [ever] greater" (2 Thess. 1:3).
 "the churches of Macedonia… their abundance of joy and their deep poverty overflowed in the wealth of their liberality… [they gave] of their own accord, begging us with much urging for the favor of participation in the support of the saints" (2 Cor. 8:1-4). "Philippi… is a leading city of the district of Macedonia" (Acts 16:12).
 "abound" is imperfective (viz., present subjunctive) and also emphasizes the ongoing nature of this growth.
 1 Cor. 8-9, Eph. 5:25-30 and 1 John 3:16-18, respectively.
 Approving the excellent things is more simply translated as "discern what is best" (NIV). The Greek word for "approve" (do-ki-ma-zō δοκιμάζω) has to do with testing—a testing that determines with certainty whether something passes or fails. This describes a firm determination.
 "excellent" literally means "different toward the better" and describes superiority of one thing over another.
 "to be sincere and blameless" is more explicitly "you would be sincere and blameless" in the Greek.
 "until the day of Christ Jesus" is more accurately "for the day of Christ Jesus."