What was this demonstration of unity in the Roman culture and city on display in the church and not visible anywhere else? This incredible new community living life together in genuine love was a res novum, a foreign object, like an alien spaceship landed in the middle of Roman life and customs. This is exactly what Christ prayed would happen in John 17. Paul reminds the Roman church that this life together is not just for our own benefit and sweetness (Ps 133:1) but to render to God’s glory; to bring praise to God. That means people who cannot see God will know God by seeing the unity of the Christian community. Unity has a powerful witness. Let’s guard it and sacrifice our preferences for it.