While I wasn't previously familiar with Sloterdijk, I find it interesting that he takes exactly the opposite value from Christianity as Slavoj Zizek, the other great popular atheist apologist for Christianity (cf. Zizek's The Fragile Absolute: Why the Christian Legacy is Worth Fighting for).

"Sloterdijk’s ideal is not Pauline conversion but Trinitarian 'perichoresis,'"

Unfortunately, I don't think Sloterdijk has understood the theological context of perichoresis which he goes on to define:

"'Perichoresis means that the milieu of the persons is entirely the relationship itself,' he writes, envisioning love as a total mutual absorption."

Perichoresis is literally "mutual interpenetration" and refers to the greek choros and their dances around (peri) each other in interlocking rings in the theatre. In the theological appropriation of this imagery, this has more to do with the depth and interdependence of the relationship than with the "milieu" - though it's not clear what he means by that.