The Christian religion as a religion is not of God. It is on the contrary another example of a mortal road to God like the Buddhist or any other, although of course different in form. Christ is not the bringer of a new religion, but the bringer of God, therefore as an impossible road from man to God the Christian religion stands as other religions; the Christian can do himself no good with his Christianity, for it remains human, but he lives by the grace of God, which comes to man, and comes to every man, who opens his heart to it and learns to understand it in the Cross of Christ; so the gift of Christ is not the Christian religion, but the mercy and love of God which culminate in the cross.
Dietrich Bonhoeffer, Essay: “Jesus Christ and the Nature of Christianity”