Does this thread pick back up in the second book? What was the intended purpose of including it in the first place? It in no way influenced the plot or even came close to the main plot thread.
The only thing I can presume is when the Space Marine is teaching the young Primaris about how the Belief in the divinity of the Emperor makes humanity do strange and miraculous things, which sort of proves the divinity of the Emperor. Was this an example of that? Because in the end it was all a waste, right?