From C.S. Lewis's essay (warning: the online version has quite a few typos) "Christian Apologetics",
For my own part, I have sometimes told my audience that the only two things really worth considering are Christianity and Hinduism. (Islam is only the greatest of the Christian heresies, Buddhism only the greatest of the Hindu heresies. Real paganism is dead. All that was best in Judaism and Platonism survives in Christianity.) There isn’t really, for an adult mind, this infinite variety of religions to consider. We may salva reverentia divide religions, as we do soups, into “thick” and “clear.” By thick I mean those which have orgies and ecstasies and mysteries and local attachments: Africa is full of thick religions. By clear I mean those which are philosophical, ethical, and universalizing: Stoicism, Buddhism, and the Ethical Church are clear religions. Now if there is a true religion , it must be both thick and clear: for the true God must have made both the child and the man, both the savage and the citizen, both the head and the belly. And the only two religions that fulfil this condition are Hinduism and Christianity. But Hinduism fulfils it imperfectly. The clear religion of the Brahman hermit in the jungle and the thick religion of the neighboring temple go on side by side. The Brahman hermit doesn’t bother about the temple prostitution nor the worshiper in the temple about the hermit’s metaphysics. But Christianity really breaks down the middle wall of the partition. It takes a convert from Central Africa and tells him to obey an enlightened universalist ethic: it takes a twentieth-century academic prig like me and tells me to go fasting to a mystery, to drink the blood of the Lord. The savage convert has to be clear: I have to be thick. That is how one knows one has come to the real religion.