I’m not a fan of rape as a plot point in any fiction, Christian or otherwise.
It’s become an overused way of showing a female character’s tragic backstory (and it’s always a female character). I’m especially not a fan of on-the-page rape scenes as they generally come across as voyeuristic and violent, as though they are there for the cheap thrill rather than to move the plot along.
People who have experienced sexual violence don’t need the reminder, and people who haven’t don’t need to have the details spelled out in order to understand that the character is going to be negatively affected.
I’m even less interested in Christian fiction that will show rape (which is nonconsensual and unlawful) but won’t show consensual sex in marriage. I’m not saying I want to read explicit sex scenes in Christian fiction (I don’t), but I do see it as hypocritical if sex is only described when it’s the unlawful, undesireable kind.