Do Thomas and John need to agree before world Christianity is unified?

Very interesting report here from Brett McCarcken in Christianity Today on two conferences in the States, both raising, in different ways, what it takes to achieve Christian unity:

' "Nothing justifies schism." This was the sober, stone-faced, and curiously truncated response by N.T. Wright when asked—at last week's Wheaton College Theology Conference—what might justify such action. The question wasn't theoretical: he currently serves as Bishop of Durham in the Church of England.
I attended the Wheaton Conference one day after attending another conference—Together for the Gospel (T4G)—which took place in Louisville and featured a who's who of "Young, Restless, Reformed" leaders/pastors for whom Martin Luther's ultimate schismatic act stands as one of the greatest, most heroic, God-ordained actions in Christian history.
The juxtaposition of these two sold-out conferences, which represent two of the most important strands of evangelical Christianity today (the neo-Reformed movement and the "N.T. Wright is the new C.S. Lewis" movement), made the question (problem?) of unity within the church impressively pronounced.'

The whole document is here.

Very interesting thinking whether we are most agreed when affirming our faith together or defending our faith together. And, what would it take to get Thomas Wright and John Piper to talk to each other, not past each other.