For Paul correct thinking must lead to right living. Having thus concluded the first application by urging the Philippians to conform their behavior to what they have been doing in the past, he now presses that point again, but especially in light of some who do not. As in verse 13, he emphasizes the repetition with the vocative, brothers [and sisters]. At the same time he also returns to his more standard language of "walking" (NIV live; see commentary on 1:27) and "imitation" (NIV following). Thus, in keeping with his Jewish heritage, Paul urges his friends to join "together" (not with others; see note) in "imitating me," again emphasizing their being united in doing so, by "walking" as Paul himself did.
What is in view from his heritage is the pupil who learned not simply by receiving instruction but by putting into practice the example of the teacher; the one who so imitates, internalizes and lives out the model presented by the teacher. Also in that heritage ethical life was thought of in terms of "walking in the ways of the Lord." Thus Paul urges the Philippians to take note of those who "walk just as you have us as a model." The grammar and language of this clause imply a group of people that extends beyond the Philippians themselves. Along with "watching out for" the itinerants who would "mutilate" them (3:2), they are to "take note of" or "be on the lookout for" people (probably other itinerants) who, like themselves, walk in keeping with the example they find in Paul.
Three matters are thus brought together in this second application: (1) that their behavior conform to the pattern Paul has just given them in his story (3:4-14); (2) that they corporately join together in imitating Paul in this way; and (3) that they take note of others who come along who "walk" this way, precisely because, as he will spell out in the next sentence, there are many who walk otherwise.