Jamieson, Fausset and Brown on Philippians 1:9

9. The subject of his prayer for them (Php 1:4).

your love--to Christ, producing love not only to Paul, Christ's minister, as it did, but also to one another, which it did not altogether as much as it ought (Php 2:2; 4:2).

knowledge--of doctrinal and practical truth.

judgment--rather, "perception"; "perceptive sense." Spiritual perceptiveness: spiritual sight, spiritual hearing, spiritual feeling, spiritual taste. Christianity is a vigorous plant, not the hotbed growth of enthusiasm. "Knowledge" and "perception" guard love from being ill-judged.