I remember reading a SciFi or Cyberpunk story some three or four years ago. It was an E-pub and I remember the title containing some color, but I can't seem to find it again.

The story is about some security expert or hacker that is working for a company. The main character get messages from a (deceased?) friend or old colleague, and over time does join a church or cult to try and find out what happened to them. I believe that there was some kind of AI involved.