Philip Goff at the TLS:
Religious fictionalists hold that the contentious claims of religion, such as “God exists” or “Jesus rose from the dead” are all, strictly speaking, false. They nonetheless think that religious discourse, as part of the practice in which such discourse is embedded, has a pragmatic value that justifies its use. To put it simply: God is a useful fiction. In fact, fictionalism is popular in many areas of philosophy. There are, for example, moral fictionalists and mathematical fictionalists, who think that there are pragmatic benefits to using moral/mathematical language even though such discourse fails to correspond to a genuine reality (there are, on these views, no such things as goodness or the number 9, any more than there are dragons or witches). Religious fictionalists merely extend this approach to the statements of religion.
What is the pragmatic benefit for the atheist of using religious language? The religious fictionalist Andrew Eshelman proposes that religious discourse can be understood as mythological, by which he means “a meaning-loaded narrative that has been adopted by a particular community to give expression to and foster a form of life defined by its guiding ideals”.