What have the church fathers or notable theologians written about how God chooses specific times, places, and people for major conversion experiences?

My earlier question https://christianity.stackexchange.com/q/103636 received the following criticism in the comments: > Rather than asking for truth about a religious concept, ask something like *"What, if anything, have the church fathers or notable theologians written explaining how God chooses specific times, places, and people for significant conversion experiences?"*. That asks for objective facts (e.g. "Martin Luther wrote "…") as opposed to subjective opinion (e.g. *"It is absurd to ask …"*). Most of us might agree with that opinion, but it is still an opinion. Whereas Catholics, Hindus, and Atheists would all agree with the statement about Luther, even though they all disagree with what Luther said. Thus, I ask: **What, if anything, have the church fathers or notable theologians written explaining how God chooses specific times, places, and people for significant conversion experiences?**