Gods

Whether or not people believe in the gods, they swear by the names of the gods that they are used to hearing. How long will atheists continue to say "Christ"? Sf authors presenting narratives set in past, future or alternative times often convey to the reader that this is a different time or timeline by telling us how their characters swear. In Ray Bradbury's The Martian Chronicles, an Earthman on Mars where the Martians are extinct meets a Martian who is either from the past or from the future - the latter would mean that he is a descendent of Terrestrial colonists. They say, "Jesus," and "gods," respectively.

In one Poul Anderson future, the characters swear by Cosmos, which communicates to the reader that an entirely different world view has become prominent, referring neither to personal deities nor to anything supernatural. SM Stirling's Eric von Shrakenberg sounds extremely archaic when, early in Marching Through Georgia (New York, 1991), he refers to "...the White Christ and Almighty Thor..." (p. 32). Is he in a timeline where, in 1941 when there are airdrops on Sicily, Christianity still contends with Norse Paganism? No. The Draka have adopted a lifestyle that makes it impossible for them to remain even nominally Christian. References to Christ are likely to convey their hostility to that belief system. Furthermore, there had been:

"...a failed attempt to revive the Old Faith back in the last century." (p. 89)

This has resulted in figurines of Thor and in Eric's father being familiar enough with the old myths to say:

"'Even you couldn't lift the Midgard Serpent or outwrestle the Crone Age, eh, Redbeard?'" (ibid.)

Odin One-Eye, Loki, Frey and Heimdall are also invoked in casual conversation so the attempted revival, even if it failed, has been effective enough to alter habits of speech.