Abstract: While the public values of Christianity concern about the "should be", the sociality of Christianity relates to the "should have been". Therefore, the sociality of a religious system directly limits its commonality and controls its public values concerns and its existing social forms. For the modern social structure, where there is sociality, there is commonality. And this sociality, being outside the state power and the economic market, once its function works, makes all the religious systems embody a kind of public rationality that is both necessary for the modern society, and free from the state power and the economic market.

Key words: Christianity, public values, sociality, commonality, religious sociology