E.B. Benjamin, a critic, points out Robinson Crusoe is far more than the account of a practical man's-adjustment to life on a deserted island. Side by side with Crusoe's physical conquest of nature, is his struggle to conquer himself and to find God. The spiritual crisis in Crusoe's life on the island is the core of the novel from this point of view. Under the stress of the hardships of life on the island, and more especially under the strain of his illness, Crusoe undergoes what may be called a transformation. During his illness he sees a frightening dream in which a man, having descended from a cloud, threatens to kill him with a spear. This dream may be regarded as a kind of a supernatural warning or a supernatural piece of guidance to him. On waking up from this dream, Crusoe recalls the excellent advice which his father had given him, but to which Crusoe had paid no heed. He now remembers that, during the past eight years since he left home, he had not looked upwards to God with any sincerity of feelings even once. Tears now begin to flow from his eyes, and he prays to God for help. This, Crusoe tells us, was the first prayer which he had ever addressed to God for many years. Here we have a turning-point in Crusoe's spiritual life. From this time onwards, his mind is essentially at peace; and the rest of the book is in the nature of an account of the due rewards and powers of the man who has been spiritually saved, The description of Crusoe's conversion has a peculiar force and intensity, so that we cannot avoid regarding this incident as central to the meaning of the whole book.
According to a critic Robinson Crusoe’s behaviour on the island reenacts a drama of religious conversion, and is not an experiment in the effects of solitary confinement. Crusoe loses twenty-eight years of sinful life, but he gains an eternity of bliss. At the moment of his conversion, he cries aloud in a kind of joyous ecstasy: "Jesus, thou son of David, Jesus thou exalted Prince and Saviour, give me repentance." According to this view, Crusoe's captivity on the island was primarily theological and only incidentally geographical; it was captivity in sin, and he is liberated from sin and the consciousness of sinfulness through repentance and devotion to God. Thus the account of Crusoe's victory over nature on the desolate island is allegorically his victory over himself and also the establishment of a close relationship between him and God.
Some other critics have offered other allegorical interpretations of the story. The story of Crusoe can be read as a version of the Biblical story of the prodigal son. Crusoe himself makes an explicit reference to this Biblical story when he says, at the end of his initial voyage, that, if even now he had returned home, his father would have forgiven him and would have given him an enthusiastic and joyous welcome. In other words, Crusoe is the prodigal son who leaves his father's house against his father's advice, who ruins himself not by his dissolute living, but by his roaming disposition, who is then left solitary and desolate, who repents of his disobedience to his father, and who eventually returns to God the Father. On the island, God the Father, as it were, kills the fatted calf, blessing Crusoe with an abundance of everything and restoring him to favour and to a sense of proprietorship of property. The climax of divine benevolence comes when Crusoe recognizes the fact that he has been treated by the Creator most mercifully, and that God has sweetened his bitter life on the island with His generosity. "What a table was here spread for me in the wilderness, where I saw nothing at first, but to perish for hunger!" says Crusoe. He now imagines himself as the prince and lord of the whole island, with the lives of all his subjects (namely his pet animals) at his absolute command. "Then to see how like a king I dined, all alone, attended by my servants." Thus the prodigal son finds himself rewarded amply and liberally. The same critic further suggests that the novel may also be interpreted in more abstract theological terms. Crusoe is Every-man, abounding in original sin, falling into specific folly and crime, incriminated more and more through repeated opportunities granted to him by God for amendment, yet one of the Elect whom God mysteriously reserved to be saved through chastisement.
Another way of looking at this novel is to regard it as an allegorical expansion of the idea of man's isolation and loneliness. In the last analysis, every human being is alone, and is condemned to solitary-ness. A man may live in the midst of crowds; he may dwell in congested cities and towns; but a man is essentially alone. No man can communicate with any other man, not even with his closest friends and relations, and not even with his own wife and children, in the true sense of the word. No man dares to reveal his innermost thoughts and feelings to anybody else. Each one of us has certain secret thoughts, certain secret longings and cravings, which we cannot confide to anybody else. We do experience an urge to share our feelings and desires with somebody else; but we simply dare not do so because of the fear that others /would feel shocked by our disclosure. Thus, each of us remains alone, with himself. It is this-situation which is symbolized by Defoe's novel in which the character called Robinson Crusoe finds himself alone, with himself. Crusoe, of course, ultimately finds God and draws comfort from his relationship with God. Perhaps we too can also draw comfort by establishing a similar relationship with God. Defoe's novel is, in this sense, a dramatization of universal experience: "We are all Crusoe, for to be Crusoe is the human fate." One critic has described this novel as an "epic of solitude".
One scholar found in this novel a prophecy of empire, with Crusoe in the leading role of a colonizing Englishman. Now, it is true that Crusoe eventually turns the island into a colony and becomes the master of one half of it. He converts his whole prolonged stay on the island into a kind of commercial investment which brings him rich dividends. In the beginning, Crusoe regards his island as the island of despair; but afterwards the same island becomes a kind of paradise. Towards the close of the novel, we are told that Crusoe revisited his island and entered into an arrangement with the settlers there, by which he would own half of the island as his private property. Thus, it would be quite legitimate for us to regard Crusoe's whole experience on the island as a step in the direction of colonization. Subsequently, the English people did colonize some of the remotest parts of the world and they became the masters of what came to he known as the British Empire. This interpretation is acceptable to us, especially because Defoe's own view of himself was that he was a maker of projects, and because one of his favourite projects was to colonize the Guianas which he believed to be rich in gold.
According to some critics, Robinson Crusoe is also an allegory of the life of the "homo economicus" or the economic man under certain peculiar conditions. According to this view, Crusoe on the desolate island behaves as any man would behave in any society where the individual is free to improve and raise his economic position by his own unhindered effort and by his spirit of enterprise and initiative. Crusoe prospers on the island just as he might have prospered in a social context by his own ingenuity and sagacity. From this point of view the novel becomes a plea for economic individualism or for the theory of laissez faire.