When when I am on the phone and my mom starts complaining about the same three things that she has power to do something about but doesn't and saying nonsense she heard on right wing stations ("All lives matter" ) I just put the phone down next to me so I don't run screaming out into the street. Then I pick it up and make acknowledging noises until I can hang up.
You could quickly train her to avoid religious subjects by acting bored and mumbling, "Um, hum..that's nice," then say you enjoyed talking to her, but you have to run.
Only give her encouraging feedback if she is talking on neutral subjects in a friendly manner.
You can train her in three tries, as I did my parents. People don't like being ignored.
But you have to be consistent.
You have my sympathy. I don't talk to mine anymore. The big bonus to that is not having to listen to her bitch, piss, and moan about every single thing that has ever happened. If she doesn't have a current thing to bitch about she'll drag up some shit from the past to bitch about. And she can find something to bitch about, about damn near everything.
I can't even begin to tell you how much happier I am not talking to my mother.