What is called "bad language" is generally not acceptable in Christian fiction. This, despite the fact that God used, well, rather interesting language in the Bible. Of course, exactly how interesting it is gets obscured by translations. Probably because the same publishers think it would be hard to sell a Bible with "those words" in it.

This, despite the fact that the venerable KJV has the word "piss" in it twice (2 Kings 18:27 and Isaiah 36:12) and "pisseth", six times (1 Samuel 25:22, 34; 1 Kings 14:10, 16:11, 21:21; 2 Kings 9:8). Certainly no modern translations would dare do that.

But despite the best efforts of translators to obscure certain unsavoriness, some things just can't be hidden. Check out Ezekiel 23:20:

"There she lusted after her lovers, whose genitals were like those of donkeys and whose emission waslike that of horses."

Of course, there are other interesting passages. In fact, Ezekiel 16 and 23 quite graphically describe Israel and Judah as prostitutes. Ezekiel's purpose was to shock his listeners, so that they would understand just how hurt God was by their lack of faithfullness to him by their chasing after idols.

Strangely, it would be hard to do anything similar in modern Christian fiction. This strikes me as both hypocritical, and shortsighted. The fear of allowing characters to be real people, to struggle, and to sometimes be unpleasantly vile, makes for very bland work most of the time.