I have yet to play a game of Civ 7 where I've really engaged with the religion system. I hate micromanaging missionaries. Also, any real benefits you get are buried behind the scenes, so you don't have the satisfaction of really seeing the impact of leaning into religion. Some ideas to make things more interesting:
1. Add faith as a currency
- Unlocks in Exploration
- Similar to Civ 6 for generation & purchases, except:
- Settlement has access to multiple faith buildings based on religions present
- Religion-unique buildings provide faith back to founder
- Can be used for special endeavors/sanctions
2. Convert population passively with pressure
- Similar to Civ 6 except:
- "Religious population" & "Religion presence" are independent variables
- Population = # of "believers"; presence = % distribution of religions among believers; followers = population * presence
- Faith buildings/wonders replace holy sites
- Towns/Cities generate different amounts of pressure (e.g. town specialization)
- Civ's/settlement's "majority religion" is the one with the most followers (starts as "non-religious")
- Once presence exists, will always have minor presence unless purged
3. Replace units/conversion with Envoy-like missionaries
- Missionaries get assigned to a settlement, like civ 6 envoys
- Time to establish based on distance from nearest religion presence
- Once established, generate pressure until reassigned/purged
- Multiple missionaries from multiple religions can be in the same settlement
- Use faith/diplo action to purge foreign missionaries/religions for relationship penalty
4. Add a separate theology tree
- Nodes unlock beliefs/policies/bonuses/buildings/wonders/units/missionaries
- Include benefits for not founding a religion
- Progress based on religious population
- Unlock counters/boosts for religious pressure (e.g., from science and/or influence buildings)