Tech support informed me on Tuesday evening, "Preliminary results ... indicate a hack on the server."
A backup restoration is in process. Nothing prior to Monday morning will be lost, if all goes well.
It may take a while yet, but the blog will be back.
Thank you for your patience.
Thinking Christian Blog
Tech support team:
Please feel free to take this index file down and replace it whenever you wish.
The original WordPress index.php file has a new name on it, which you'll recognize easily enough when you see it. (I expect you'll replace it all anyway.)