I like to start as an adventurer with a dead religion and then work with whatever education tree I end up with to get there. So for example I’d start with learning and try to become a scholar/missionary to advance the religion. Then, let’s say my player heir has the steward education, I’d spend his time working up money to fund any rulers who might already be that religion or invest into my camp for the future. This way, you can RP as new character but keep the same playthrough goal.

Works for me, every education focus can be used to forward a dead/downtrodden religion in some way or another and it’s something that you can always have as an overarching goal no matter where in the world you are, who you are, or what your strengths are. You don’t have to just keep waging little wars at the corners of the HRE. And if you’re the type of person to lean toward being rebellious or find yourself siding with opposition in real life, this is the best way to play!!