Philippians 2:1 So if there is any encouragement in Christ, any comfort from love, any participation in the Spirit, any affection and sympathy, [2] complete my joy by being of the same mind, having the same love, being in full accord and of one mind. [3] Do nothing from selfish ambition or conceit, but in humility count others more significant than yourselves. [4] Let each of you look not only to his own interests, but also to the interests of others.

Christian unity is possible only when the Gospel empowers you to kill pride and practice humility.
     I.  Embrace Gospel Truth 1
    II.  Kill Your Pride 3a
   III.  Practice Humility 3b-4
    IV.  Rejoice in Unity 2