Dietrich Bonhoeffer said the following in “Sermon for Evening Worship Service on 2 Corinthians 12:9 London, 1934”:

“Christianity stands or falls with its revolutionary protest against violence, arbitrariness and pride of power and with its apologia for the weak.—I feel that Christianity is rather doing too little in showing these points than doing too much. Christianity has adjusted itself much too easily to the worship of power. It should give much more offence, more shock to the world, than it is doing. Christianity should […] take a much more definite stand for the weak than to consider the potential moral right of the strong.”

Source: Dietrich Bonhoeffer, London: 1933–1935, ed. Hans Goedeking et al., trans. Isabel Best and Douglas W. Stott, vol. 13 of Dietrich Bonhoeffer Works (Minneapolis, MN: Fortress Press, 2007), 402–403.