In addition to @steelersquirrel's answer, the dynamic between Chirrut and Baze comes from what inspired George in The Hidden Fortress. As per words by Lucasfilm President Kathleen Kennedy,
Lucasfilm President Kathleen Kennedy has said the dynamic between Chirrut and Baze comes from what inspired George in The Hidden Fortress, referring to the great Akira Kurosawa movie. “You could even say to some extent its, you know, R2 and C-3PO, a little bit of that.”
Jiang Wen, who portrayed Baze Malbus, says
"He and me was a partner and he believe of course, believe in Force. But my character don’t believe Force at that time. But I pretend all of them, not them, just them, to do very, very big mission. I cannot say that. And when this guy dead, I do something better. Maybe I believe, by my action, he’s thinker, I’m doer."
So, they were just partners.