Confession

Operation Luna.

Ginny's brother is put through a "'...psychoscopy...,'" (26, p. 239) which must be the goetic equivalent of a hypnoprobe or a kyradex. (Scroll down.)

Steve tells his brother-in-law that the government investigators:

"'...keep confessions under seal same as priests or doctors.'" (29, p. 259)

Once when I sat to meditate in St. Wilfrid's Church, Preston (see image), a man approached and asked if I knew whether anyone was hearing confessions. I had to say no. I was there to practice a different religion. (The public are invited to enter to pray or mediate.) A woman came in and practiced yet another, walking around kissing the statues of saints. Sometimes, if you sit or kneel in a church, someone watches you, then follows you out and asks you for money.

Ian Hislop said on TV that journalists tried to pay his vicar to learn whether he had said interesting in confession! Agatha Christie's Poirot cannot receive absolution from a priest because the priest would insist on Poirot first confessing murder to the police and Poirot, for his own purposes, needs to disguise the murder as suicide so he directly asks God to forgive him.

Of Poul Anderson's Technic History characters:

Nicholas van Rijn and Admiral Cajal are Catholics;
I deduce that Eric Wace is also Catholic (see here);
Philippe Rochefort and Francis Xavier Axor are Jerusalem Catholics;
Dominic Flandry's fiancee, Kossara Vymezal, is an Orthochristian, later canonized.

These six characters would confess sins to a priest.

We also see Catholicism and several other religions survive into SM Stirling's Emberverse.