Paul treats unity like an honor-budget: if you keep spending it on yourself, the church goes broke.
Fulfil ye my joy, that ye be likeminded, having the same love, being of one accord, of one mind. Let nothing be done through strife or vainglory; but in lowliness of mind let each esteem other better than themselves. Let this mind be in you, which was also in Christ Jesus: Who, being in the form of God, thought it not robbery to be equal with God: But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men: And being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross. Wherefore God also hath highly exalted him, and given him a name which is above every name: That at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth; And that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father. Wherefore, my beloved, as ye have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling. For it is God which worketh in you both to will and to do of his good pleasure. Do all things without murmurings and disputings: That ye may be blameless and harmless, the sons of God, without rebuke, in the midst of a crooked and perverse nation, among whom ye shine as lights in the world; Holding forth the word of life; that I may rejoice in the day of Christ, that I have not run in vain, neither laboured in vain. … Receive him therefore in the Lord with all gladness; and hold such in reputation: Because for the work of Christ he was nigh unto death, not regarding his life, to supply your lack of service toward me.
Paul treats unity like something you can spend. Spend it on yourself, and the church goes broke. Philippians 2 names the quiet way a community frays: people start keeping score. Who gets heard, who gets credit, whose preferences set the temperature, who feels slighted. In Philippi, a Roman colony, status was normal air. Rank told you who mattered. Paul does not pretend that instinct disappears when you become a Christian. He faces it and gives a counter-habit: “Let nothing be done” for ego, and start treating the other person as heavier than you. That is not a mood. It is a decision about where the group’s attention and praise will go, and it has to be deliberate because the default is competition.