With the prevalence of religions ascribing a continuation of life beyond the grave, one could assume that no religion could "survive" without allowing for a continuance of life. The very concept of an afterlife plays upon the apparent human vanity of needing to believe that something lies beyond our comprehension, beyond simple mortality. It is akin to gamblers spending their money on the "sure thing", hoping that eventually it will pay off.
It seems impossible that a religion could be viable if it did not offer something for its worshippers that did not entail supernaturality. The struggle would be to convince people that while this is the only life that they will ever know, that once their mortal life is over, nothing comes after. As such this religion must find a compelling argument that it is in this existence that a person can find a kind of salvation that has meaning. And this is where the religion without an afterlife must find a way to counter the warning of Shelley's Ozymandias.
This religion, call it Nowism, must be founded on the belief that it is in this mortal life a person must strive to become the purity of its god. Since there is no afterlife to segregate the pious from the non, reward and suffering must manifest itself in the now, and be a direct reflection of the individual. If a person lives his/her life poorly, evilly, then the person will find naught but evil returning and plaguing his/herself.
Nowism has many examples as tools to convince people of its possibility. One could argue that the vanity, the covetness, of people have brought great suffering to the world. Global warming, wars, genocide, and crime in general, are indicators of evil wrought by one's own hands. Nin attributes it to maleness and passivity of women. It is not the role of god to end these violations, but squarely in the hands of the followers. If they were to examine their lives, as Socrates urged, they would know that they have not lived in piety, but in irreverence, and as such, the forces of the universe have repaid them with the penalties of their actions.
Instead of offering salvation at some later time, Nowism could offer salvation every day with every action. At the same time it would offer damnation at every action as well. Nowism would border closely to the Sartreian maxim of man, in the absence of god, creating himself. But man creating himself would not be to establish morality from situation to situation, but through reflection of end results. If killing a bad person would save a community from evil, then is it the moral thing to do? Hegel has made the point that the punishment of the criminal must not be determined as though he were a "harmful animal" that must be made harmless.
Since that is so, punishment is regarded as containing the criminal's right and hence by being punished he is honoured as a rational being. He does not receive this due of honour unless the concept and measure of his punishment are derived from his own act. Still less does he receive it if he is treated either as a harmful animal who has to be made harmless, or with a view to deterring and reforming him. (Philosophy of Right, §100).It puts the emphasis for actions squarely in the hands of the individual.
And an interesting possibility for Nowism is that a god of some sort would not be necessary. In this regard it would more closely approximate the Eastern religions which weigh a person's life by their actions. What would be missing from Nowism though would be reincarnation. It would be an escape from Nietzsche's Eternal Recurrence. A person would have but one shot at living a pious life, to generate as much good as possible. Since humanity seems to need something beyond the grave, Nowism could emphasize the reward of eternal recognition, much the way that Gandhi is venerated. There is no proof that Gandhi lives in some supernatural world, but memory of his actions and of him are quite alive still.
As interesting as Nowism would be, it would most likely fall by the wayside, would lose out to the religions that offer something more beyond this life. Nowism would face an uphill battle to win converts from the self-obsessed, from those that an afterlife must exist for. It is because of this that a religion without an afterlife is not viable. It offers mankind nothing more than is available now. And yet, Nowism appears to be a more plausible answer to the question of life.