The Attempt at a Critique of All Revelation was Fichte's first published work. The first edition appeared in 1792, a year before Kant's Religion within the Boundaries of Mere Reason. Given its obvious Kantian inspiration and the fact that it appeared anonymously, it was mistakenly thought by some to be Kant's own promised work on the subject of religion. Religion, especially the question of its relation to reason, was a topic that Fichte addressed throughout his academic career. His unorthodox views on this topic caused him some major problems, most notably his dismissal from his professorship at the University of Jena on account of accusations of atheism that were made against him. This new edition of a previously published translation of the Attempt at a Critique of All Revelation – the main change is the replacement of the previous introduction with a new one by Allen Wood – therefore provides an important source for understanding both Fichte's appropriation of Kant's Critical philosophy and the development of his own views on religion.

The work itself seeks to explain the phenomenon of revelation in terms of certain a priori principles of practical reason. It begins with a long account of the concept of the will, which was later to form a central theme of Fichte's major work on ethics, The System of Ethics (1798). Fichte's analysis of the concept of the will contains many features familiar from Kant's moral philosophy. These include the notion of spontaneity and the feeling of respect that arises from the consciousness of a law that is categorical in form. There is also the idea of a happiness that is justified by one's worthiness to be happy, a worthiness which is determined by the extent of the conformity of one's actions with moral duty. Here we see Fichte appropriating Kant's account of the existence of God as a postulate of pure practical reason in the Critique of Practical Reason. The concept of God is deduced by Fichte as that which must be thought to be necessary with respect to the establishment of complete harmony between an individual's morality and his or her happiness. The method Fichte employs looks forward to his deductions of the concept of right and the concept of morality as conditions of self-consciousness in the later Foundations of Natural Right (1796–7) and The System of Ethics, though its dependence on the content of Kant's Critical philosophy means that it lacks the originality of these later deductions.

The concept of revelation is likewise deduced from the existence of a practical need. Finite rational beings are subject to two essentially different, independent causalities, namely, that of natural laws and that of the moral law. Revelation is necessary when the moral law loses its causality altogether in such beings, which happens when their sensuous natures take over completely. The only solution then is for people to be determined by sensuous stimuli that awake (or reawaken) the causality of the moral law in them. This is the function of revelation, which has a moral content that is brought to human consciousness by means of the senses in the form of the representation of God as lawgiver and moral judge of all rational beings, who has proclaimed himself as such by means of a supernatural effect in the world of sense. Fichte makes clear, however, that this deduction establishes only the possibility of the concept of revelation, but not its objective validity, that is, the actual existence of an appearance corresponding to this concept in the world of sense. This raises the question of the possibility of such an appearance, which Fichte discusses from various angles in the following sections of the Attempt at a Critique of All Revelation in relation to the notion of applying the concept of revelation to an appearance in the world of sense. The notion of applying a concept prefigures the method of not only deducing a concept, thereby demonstrating its necessity, but also exhibiting the possibility of applying it to the conditions of the sensible world, so as to make philosophy into something more than a merely formal science, developed in the works of his Jena period.

While Fichte's enthusiasm for Kant's Critical philosophy is evident throughout the Attempt at a Critique of All Revelation, Fichte does not regard himself as simply following Kant. Rather, he considers himself to be offering various amplifications and illustrations of what he takes to be Kant's position, thereby rendering the latter less forbidding and obscure. This is evident from his claim made early on in the work in his analysis of the concept of the will that this analysis ‘has had also the secondary aim of clearing up some obscurities in the critical philosophy in general and opening a new door by which those who had hitherto been unacquainted with it or had opposed it might enter into it’ (22). Given the obscurity and diffuseness of parts of the Attempt at a Critique of All Revelation, the extent to which Fichte really achieves this secondary aim is questionable. Nevertheless, among the possible amplifications and illustrations that he offers are some statements that demonstrate the boldness of his thought and point ahead to later developments in the critique of revealed religion. There is, for example, his claim that: ‘The idea of God, as lawgiver through the moral law in us, is thus based on an alienation of what is ours, on translating something subjective into a being outside us; and this alienation is the real principle of religion, insofar as it is used for determining the will’ (41). While this claim looks forward to Ludwig Feuerbach's critique of religion, it can be seen as merely stating the implications of Fichte's earlier claim that the belief in God is only subjective, in the sense that it derives from a practical need that is a result of our finite natures. This view of the matter accords with Kant's own claim in his account of the existence of God as a postulate of pure practical reason that the moral necessity involved is subjective in kind. Fichte's willingness to draw this implication in such radical terms nevertheless provides an example of how the Attempt at a Critique of All Revelation represents a harbinger of things to come with respect to his own later writings.