Choosing gods at your temple.

[Lion.Kanzen]

I suggest in polytheist

One for warfare.

One for Agriculture

And other may be for love or Mother Nature, even for metalworking, dead or whatever.

[oshron]

In AOM, choosing a Major or Minor god affected all kinds of supernatural things, like monsters, God powers, religious or mythological bonuses (techs), but in 0 A.D. we have none of that stuff. In real life, how did worshipping Athena affect a nation's economy or military might over worshipping Artemis? Likely worshipping either wouldn't have made a difference at all. See what I'm saying?

Unless there's some kind of thing where you get diplomatic bonuses for dealing with players who have the same patron god or something like that.

it could be that you the player, representing the government of the faction you're playing as, are more correctly endorsing a particular deity, the act of which then inspires the people of that civilization to do what they do better (religious fervor, really). for example:

Player: We the Macedonians live by the sea! We intimately associate ourselves with the ocean! Therefore, we shall venerate Poseidon, god of the seas!

Sailor: He's right! Poseidon must be watching over us! Step lively, men! We have nothing to fear out on the sea with Lord Poseidon watching over us!