I've written on Medium for a few years now and only recently began writing with my faith in mind. I'd included it in other content but it wasn't the focus of it.
I think my biggest month was around $14 ... so it's not something I'll get rich from. I write here mostly as a way to reach a varied and different audience. I've written online for over 15 years through personal blogs.
It sounds like you have your goals and your priroities straight. As I work to write more on my own faith, I have been praying for His leading for this reason - I want to ensure the same! Best wishes to you and thanks for sharing!