Different game modes???

Which one gives you the most rewards?

Technically you would get the most rewards by doing every game mode and getting their first win of the day since each of them give good favor. However, if you just want to do one, I would say Arena games are the fastest so you'd probably get the most frequent rewards there, however Conquest games provide you with the widest amount of knowledge and skill (also take into account that longer games usually yield more favor regardless).

TLDR: play what you like, if you really want more favor farm first wins.

I usually do a lot of arenas. It's fast and it's also really fun and rewarding.

it depends on what you mean favor is by getting the 1st win and after that on winning and on duration of the game mode. (winning has a bonus of 50) also a high goodwill (100%) will give 30% more favor.

for casual/normal
worshippers is the best gain able in Conquest as the win bonus on worshippers is 5 and you get 1 worshipper every 4 minutes (0.25 a minute).
while all other game modes yield a win bonus of 4 and only 1 worshipper every 5 min (0.2 a minute)

ranked has the best yield with the same win bonus and a worshipper ever ~3.20 minutes (0.3 a minute)

bot games only yield xp and a little bit of favor and will never give you worshippers.

happy grinding