James H Cone's 'A Black Theology of Liberation' is his attempt at creating a systematic form of theology, developing the ideas he first put forth in 'Black Theology and Black Power'. Insofar as he attempts to do this, he provides a reasonably coherent theological method, one that is certainly more developed (and more coherent, if no less coherent) than his proceeding tome. Where Cone fails, however, is his continued self-righteousness, in attacking "white theology" and his stigmatisation of white people and "white theology" as satanic, basing this analysis on deeply flawed (and deeply racist) logic:
'American white theology is a theology of the Antichrist insofar as it arises out of an identification with the white community, thereby placing God's approval on white oppression of black existence.' [Cone, 'A Black Theology of Liberation' (1986) p.6]
The first problem is the assumption of the existence of "white theology" as though such a theological method has ever actually existed: history shows that there have been many streams of theological thinking, some orthodox some heterodox. (Cone's continuous quoting from both Tillich and Barth proves such a point. It also shows that not all "white theology" is flawed, only that theology of which Cone disapproves, thus disproving his own point about homogenous unacceptability of "white theology".)
The second is the assumption that somehow all "white theology" is somehow coterminous with the approval of slavery, or that white theologians have done nothing to challenge slavery, which is both historically and theological nonsense! There is also the problem of Cone's continued 'othering' of the white by Cone. He continues to utilise the 'It' 'Thou' method of turning white people from people to things, a reversal of some white culture of turning black people into objects or possessions (a form of inverse racism on the part of Cone).
There is also the overt racism within the language employed by Cone. Word such as 'Honky' and 'Whitey' are bandied around, yet are as unacceptable (and implicitly racist) as the words of abuse used by white people against blacks. There is also the argument that it is acceptable (and the work of God) to kill slave owners, as if one evil can be overcome with another. In using such language and making such an argument, Cone undermines his own point and proves the failure of his own Black Theology: in praising violence and racist language it has lost its moral compass, mistaking racism and violence for righteousness.
Cone of course has an important message about the nature of Christ. However, by arguing that the only valid form or image of Christ is that which comes out of the experienced of the oppressed means that he effectively cuts off the branch he is sitting on, from the tree. Christian theology has long come out of the experience of not just the oppressed, but also of the powerful (the theologians he is wont to quote: Barth; Tillich; and, Moltmann are each theologians who, as members of the academy, people who hold considerable intellectual power. Similarly, in writing from a Protestant/Reformed background, Cone draws on a theology of the powerful, just as he would have done if he were Catholic or Orthodox. What Cone enjoys doing is proving the self-righteousness of his own theological position, without seeking to understand or appreciate the position from which he is coming.
It is important to note that Black Theology has an important role to play and an important message to bring to the Church. What it cannot claim to be, however, is the only valid theology (a point Cone spends much of his time labouring). Theology, as he argues is contextual, it is also, however, timeless: there are timeless truths which transcend both time and space such as the Patristic Trinitarian theologies, but also the abhorrence of slavery and the inalienable humanity and Christlikeness of every human being!