Unity of God's church
The recent combined churches event, Kotahitanga, embodied Jesus' John 17 prayer...'that they may be one'.

When Jesus prayed this prayer to His Father, He never intended for unity to become uniformity or conformity. Rather, this was about diversity within the collective unity of action and outworking of His church, His called out people.
Diversity within collective unity and action of the church
All things to all men (and women!)
In the New Testament we don't see Paul urging the church to conformity, rather the church grows in a diverse way from the original vision that Peter had about the Gentiles.
Paul himself feels free enough in his own identity in Christ to fit in with the various diverse cultures he encounters as he visits the many churches that have sprung up. We see Paul abstaining from certain practices at times, yet participating in cultural ways in others:
'To the Jews I became like a Jew, to win the Jews. To those under the law I became like one under the law (though I myself am not under the law), so as to win those under the law....I have become all things to all people so that by all possible means I might save some. I do all this for the sake of the gospel' (1 Cor 9 paraphrased)
We need more times like the recent Kotahitanga, where the collective church of Jesus, for a moment, lays aside its own agendas, traditions, practices, liturgies and embraces, joining together in our uniqueness, yet in united identity of a called people one under Christ.