Historian Rodney Stark explains why the theology of God in different religions produces very different religions. All religions cannot basically be the same because their gods are not the same; some religions don’t even have a deity. The kind of god one believes in determines whether or not morality is part of the religion (some religions have no moral guidelines) and whether or not we are meant to have relationship with the deity. Some gods, as conceived by various religions, just are not capable of being moral or having a relationship with human beings. Stark explains in For the Glory of God: How Monotheism Led to Reformations, Science, Witch-Hunts, and the End of Slavery:
Whether religions generate moral culture depends greatly upon their image of God. Not only are divine essences unable to issue commandments; they cannot sustain any concept of “sin.” The Tao does not advise humans to love one another, nor does the “First Cause” tell us not to covet another’s spouse. Paul Tillich’s “ground of our being” is not a being and consequently is incapable of having, let alone expressing, moral concerns. Only Gods—conscious supernatural beings—can desire our moral conformity. Even that is not sufficient. Gods can lend sanctions to the moral order only if they are responsive and dependable—if they are concerned about, informed about, and active on behalf of humans. Moreover, to promote virtue among humans, Gods must themselves be virtuous—they must favor good over evil. Finally, Gods will be more effective in sustaining moral precepts, the greater their scope—that is, the greater the diversity of their powers and the range and duration of their influence. Besides lacking scope, the many Gods of polytheistic systems are often not conceived of as responsive and dependable, or as necessarily favoring good over evil. Among the Indians of the Northwest Coast, the Gods (such as they were) did not concern themselves with morality, and magic dominated ritual life. Aside from those involved in ascetic sects, most Greeks and Romans believed that their Gods could hear their pleas, but that they mostly didn’t listen and didn’t care. Aristotle taught that the Gods were incapable of real concern for humans—lust, jealousy, and anger, yes, but never affection. Such Gods may require propitiation, and it may sometimes be possible to bargain with them for favors. But they are not to be counted on, and it is quite uncertain that it is even wise to attract their attention. Indeed, the Gods of Greece and Rome (and of polytheisms in general) sometimes kept their word, and sometimes they provided humans with very valuable rewards. But they often lied and did humans great harm for very petty reasons...
It may have been worthwhile to periodically offer such Gods a sacrificial animal or two (especially since the donors feasted on the offering after the ceremony), but they were not worth more. Consequently, they could not ask more. In contrast, the immense Gods of the monotheisms ask much more and get it. In return for the otherworldly rewards they promise, and to enable humans to avoid the terrible punishments they threaten, these Gods uniformly impose sets of demands. And all of these sets include extensive codes of human conduct, not only toward the sacred, but toward one another...
Recently, a substantial body of anthropological and experimental evidence has been assembled to explain that variations in the importance placed on ritual precision reflect differences in the capacities attributed to the supernatural agents to which (or whom) the rituals are directed. When, as in the case of magic, the supernatural agent is an unconscious entity or is a supernatural creature of very limited capacity (such as a demon or an imp), it will be assumed that each ritual must be performed with extreme precision because the supernatural agency lacks the capacity to know the intent of those performing the ritual and is unable to overlook errors in ritual performance. As Justin Barrett put it, ritual precision is required in dealings with “dumb gods.” This same logic applies, if to a somewhat lesser extent, to religions based on Gods of limited scope. They, too, may take note not of the intent of rituals but only of their execution. Indeed, there is a substantial element of compulsion in interactions with small Gods, as well as with the creatures that are sometimes invoked by magic (see the introduction). Here, too, the rituals must be perfect; otherwise the supernatural agent will not find them binding. In contrast, the omnipotent Gods of monotheism are thought to be fully aware of the intentions of the supplicant. Consequently, rituals are far less important, and precision is barely an issue when humans deal with Gods conceived of as all-seeing—if the priest errs, Jehovah knows what was meant, and the efficacy of a prayer does not hinge on precise adherence to a sacred formula.