Perspective from DB
"I am in fact of the opinion that one can learn extraordinarily little over there [American liberal seminaries & theologically weak churches]... But it seems to me that one also gains quiet insights... where one sees chiefly the threat which America signifies for us [European Christians]."
Bonhoeffer while in NYC 1930-31
Though a tough year theologically, he realized "insights" that shaped him, theological threats to be on guard against and ills of social, prosperity gospel without the true gospel to defend against.
"In New York they preach about virtually everything, only one thing is not addressed, or is addressed so rarely that I have as yet been unable to hear it, namely, the Gospel of Jesus Christ, the cross, sin and forgiveness, death and life."
(pp. 106 of Bonhoeffer by Metaxas)