I have heard on many accounts of people who believe in something other than God to have had encounters, a voice speaking to them, a dream, etc. Some of course sound bogus, but other seem very real. For instance I heard from the late Nabeel Qureshi in this video: https://www.youtube.com/watch?v=k0D8Uz4oQck&t=5988s
About 45 minutes in he starts talking about how the Muslim faith puts trust in dreams for prophetic guidance. Since they cant directly commune with Allah, this is how they seek his wisdom especially for major life decisions. He talks about how his family chose jobs, partners, where to live, etc. through this. Some are very vivid too like the one of his mother where she planted 4 trees; 2 grew 2 didn't. Her aunt then interprets it to mean that she will get pregnant 4 times. 2 will yield children and 2 will be miscarriages. This is actually what happens.
So what do we make of this? Is God or the Holy Spirit guiding them even though they don't believe? Is it Satan trying to trick them like we hear in Job were he used fires from heaven to mimic God's wraith? Or is it just poor interpretation of the dream and some large coincidence? Clearly when you compare the facts of Christianity and the Islamic faith, there is no comparison - Christianity comes out on top and Nabeel even points this out through the video as he converts to Christianity. However, why would this happen? Personal experiences like this often define the faith of some people so I just don't understand why it happens even when the core evidence isn't there.