The 1957 Harper & Row Publishers english edition of Ludwig Feuerbach's infamous Essence of Christianity contains an all-star cast, including a foreword by H. Richard Niebuhr, a long introduction by Karl Barth, and was translated by George Eliot (a pseudonym for Mary Ann Evans, who also translated D. F. Strauss's similarly infamous book the Life of Jesus, Critically Examined). Karl Barth's introduction was taken from an essay published in 1928, and his son Dr. Marcus Barth assisted translating it. Lastly, the foreword by H. Richard Niebuhr provides a fascinating commentary on the legacy of Feuerbach, and on Karl Barth's utilization of Feuerbach's anti-theology. In this essay, I will review Niebuhr's comments on Barth's agreements and disagreements with Feuerbach.
H. Richard Niebuhr's foreword to Feuerbach (and Barth)
H. Richard Niebuhr (1894–1962) was an American theologian, most famous for his book Christ and Culture, and he is often confused with his equally famous brother, Reinhold Niebuhr (1892–1971), who was also a famous Christian theologian. In the foreword, H. Richard Niebuhr writes more about Karl Barth, and his utilization of Feuerbach, than about Feuerbach himself. (I may discuss Barth's introduction to Feuerbach another time).
Niebuhr begins by praising Karl Barth and describing Barth's theology as the polar opposite to Feuerbach's anti-theology. Karl Barth begins with a theology from above, such that God is unknown to humanity, apart from God's self revelation to humanity. Feuerbach's anti-theology is a theology from below, starting with humanity, and developing theology based on upon anthropology.
"Karl Barth . . . the most influential Protestant theologian of the twentieth century, represents the complete antithesis in religious thought to Ludwig Feuerbach. His radical objectivism in theology is arrayed against the radical subjectivism of the nineteenth century which he sees most consistently developed by Feuerbach. His concern for the revealed primacy and sovereignty of God as the starting point of all Christian reflection is directly opposed to the humanism that finds the essence of Christianity in the glorification of man and translates all statements about God into statements about man." 
Niebuhr notices Barth's odd affection Feuerbach. Most theologians have condemned Feuerbach, but Barth recommends him! Niebuhr, rhetorically asked, why is this so? Why does Barth recommend Feuerbach, when most theologians will not serious considers Feuerbach at all?
Why, in view of this opposition, does Barth seem to recommend the study of Feuerbach instead of doing what the latter's orthodox contemporaries did–condemn or banish him as a heretic, refuse him a hearing, warn all believers against the danger of exposing themselves to so subversive an interpretation of Christianity? Why does he seem to be attracted to his opponent, pay tribute to his spirit and, in part, to his intention? 
Niebuhr answers that Barth believed that Feuerbach was an instrument of God, sent to teach us that theology from below is tantamount to unbelief. Feuerbach reveals to us that theology based on anthropology does not reveal God, and to establish our theology based on our study of anthropology, is an idol that we have made in our own image. Barth believes we only know God through God's self-revelation. Therefore Barth agrees with Feuerbach's criticism of religion and theology, that is built upon anthropology.
Religiously speaking, Barth cannot follow the example of his orthodox predecessors because for him refusal to hear the opponent would be a denial of the primacy and sovereignty of God. A faith in God so unsure of itself or rather of God that it does not permit men to listen to criticism is a very shaky thing indeed. Because Barth begins with God, not only as theologian but as believing "man of flesh and blood," as believing twentieth-century man, he can see in the opponent of orthodoxy a kind of instrument of God. The faith that burns the books of unbelievers, whether it is a faith in orthodox dogma or in democracy or in communism or any of the other "hypostases," as Barth calls them, confesses its own unbelief. 
I described Feuerbach's work as an "anti-theology" because Feuerbach is a theologian, that demonstrates that theology from below results in unbelief, and hence Feuerbach's atheism is justified, because we may not believe in any idol God that a theology from below imagines. We must disbelieve in any God made in humanity's image. Karl Barth once said, "One cannot speak of God simply by speaking of man in a loud voice." Barth in in agreement with Feuerbach, that theology that takes its starting place in anthropology, leads to unbelief and atheism. Feuerbach believed that good may come from a theology from below, that there is good utility in humanity, that is worth being praised (despite his atheism). However, Barth refuses to follow Feuerbach in a theology from below, and insists that we only know God through God's self-revelation. So Barth recommends Feuerbach, so that we may know where theology from below leads. We must not avoid Feuerbach, but study his anti-theology, so that we may not be deceived by it.
Such considerations lead us close to the theological point. Barth recommends Feuerbach to students of theology in order that they may see what the outcome is bound to be of every theology that begins with man's subjective states, be they man's God-consciousness, or his sense of the Holy, or his need for a spiritual victory over nature. The theological statements resulting from such an inquiry are bound to be anthropological statements, though in a different sense than Feuerbach's. 
In the end of the foreword, Niebuhr outlines the fundamental agreements and disagreement between Karl Barth and Ludwig Feuerbach. Barth and Feuerbach agree that we may not know God through a theology from below, and we are unable to obtain knowledge of God by studying anthropology. Barth does not eliminate humanity from theology, but he believed that we only know true humanity and God in Jesus alone, unlike Feuerbach who looked for God in humanity in general. Barth and Feuerbach are also in disagreement, because Barth finally disagrees that theology from below is possible, and instead Barth pursues theology in God's self-revelation, namely Jesus, alone.
The fundamental agreement and fundamental disagreement between Feuerbach and Barth lead us close to the central issue in the religious life of modern men. Barth and Feuerbach agree on this essential point–that to believe in religion is to believe in man, that to hope that religion will save man is to hope that man will save himself, that to have faith in Christianity itself is to put one's trust in something human, personal or social. The great disagreement is that Feuerbach can so believe in man and Barth cannot; this is to no small extent the difference between the nineteenth century and the twentieth. As Barth puts it, Feuerbach and his contemporaries did not know death and misunderstood evil.
Niebuhr concludes by defending Barth from Barth's critics. Barth is not opposed to anthropology, he is not a misanthrope or an anti-humanist. Barth is not so heavenly minded, that he's no earthly good. Niebuhr is right when he proves his point by reminded us that Barth defined true humanity, by God's self-revelation in Jesus. What is true humanity? It is revealed to us in the revelation of Jesus Christ, who is the true humanity for others, as Barth wrote in the Church Dogmatics III/2.
The implication is that Barth and our time in general face the actuality of death–personal, cultural, and racial–as "men of flesh and blood" who cannot escape it by flight into spiritual existence or by joining George Eliot's "choir invisible"; that we can no longer shut our eyes to man's vast inhumanity to man. The disagreement, however, is quite falsely stated when Barth and those who think as he does are regarded as anti-humanists. They, too, are humanists though the affirmation of man is not something they make but only accept as it is made in Jesus Christ. 
Niebuhr described Karl Barth as being more consistent with Feuerbach's theology, than Feuerbach was himself. In the end, Feuerbach still followed his own anti-theology, because despite Feuerbach's atheism, he still continued in his religious affection for humanity, and continued to develop his anti-theology by studying anthropology. Karl Barth saw the idolatry in theology from below, and utilized it throughout his Church Dogmatics, and here are a few notable examples: 1) Barth rejected "religion" in his famous paragraph 17 "The Revelation of God as the Abolition of Religion" from the Church Dogmatics I/2, by demonstrating a human made religion is ultimately unbelief, and may not be harmonized with belief in God's self-revelation of Jesus; 2) In the Church Dogmatics II/1, Barth rejected Natural Revelation, because we may not know God from the natural world, and only in God's self-revelation; 3) And in the Church Dogmatics I/1, Barth opens with his famous description of analogia entis as an invention of the anti-Christ because there is no analogy of being between humanity and God, that we may establish knowledge of God based on knowledge of ourselves.
I'd like to thank my good friend, Dr. Marty Folsom, for sharing Niebuhr's foreword with me and inspiring me to write about it.
1. Feuerbach, Ludwig. The Essence of Christianity. Translated From the German by George Eliot. Introductory Essay by Karl Barth. Foreword by H. Richard Niebuhr. Translated by George Eliot. New York: Harper Row, 1957.
Related: anthropology, Atheism, Essence of Christianity, Feuerbach, H. Richard Niebuhr, Karl Barth, Ludwig Feuerbach