Ephesians 4:1-6 calls us to consider unity in diversity on the theological level:
I therefore, a prisoner for the Lord, urge you to walk in a manner worthy of the calling to which you have been called, 2 with all humility and gentleness, with patience, bearing with one another in love, 3 eager to maintain the unity of the Spirit in the bond of peace. 4 There is one body and one Spirit—just as you were called to the one hope that belongs to your call— 5 one Lord, one faith, one baptism, 6 one God and Father of all, who is over all and through all and in all. (ESV)Finally, I am considering statements like the following by David Watson on The Unity of the Church in I Believe in the Church (Eerdmans, 1985):
[T]he doctrinal basis for unity must [be] the unchangeable gospel of Jesus Christ, as given in the Scriptures as a whole. If the basis is 'the church', the immediate question will be 'Which Church?' If we attempt to come together on an aggregate of beliefs or on some lower common denominator, we shall be either more than, or less than, the church that Christ found upon the rock, against which even the gates of hell could not prevail. (p. 355)This all seems so simple and straightforward, but we are intent on "defining" and "distinguishing ourselves" from one another within the body. How do we get back to this?