In this final encouragement toward unity, Paul addresses the leadership of the church at Philippi. He began the letter by addressing the elders and deacons (1:1), now he calls for the leadership of the church to demonstrate the mind of Christ by standing firm in unity.
“Stand firm” is a common phrase in Paul’s letters. It refers to being firmly convinced of a belief. In 1:27 he used the same word to encourage the believers to stand firm “in one spirit,” so they are able to withstand any oppression they might face as a result of their faith in Jesus. Similarly, in 2 Thess 2:15 he encourages his readers to stand firm and hold on to the traditions they have been given; In Gal 5:1 the readers are to stand firm in the freedom they have in Christ and not go back under the yoke of the Law.
One of the major themes of this letter has been the unity of the church. Paul wants the church to “live in harmony” (cf. Rom15:5) by thinking the same thing in the Lord.” Paul has used a similar phrase in 3:15 for the kind of intellectually unity necessary in the church, but also in 2:2, the church must be of “one mind” if it is going to have unity (2 Clem 17:3 uses the same phrase, possibly alluding to this text).
There may be some doctrinal unity in mind here, since this is the conclusion of a section describing the teaching of someone who opposes Paul. The church needs to think correctly about who Jesus is and what he did on the cross, for example. In the context, they need to properly understand the function of the Jewish Law in the current era.
But Paul calls for unity more often in practical matters and ethical choices. The church not only has to share the same doctrine, but also practice. In a church like Galatia, doctrine was a serious problem, but in Corinth behavior seems to be a bigger issue. As he has said throughout the letter, the church has to be of “one mind,” and they should have the “mind of Christ.”
This is the real problem with unity. There are some doctrinal and ethical matters I cannot set aside in the interest of unity. Every denomination and church has some doctrinal formulation that is considered foundational as well as behaviors considered unacceptable. How do we balance important distinctions and maintain unity in the Body of Christ?