Adopting captured Civs relgion?

[KaptainK714]

I captured Celts who had adopted Christianity- they were just to pushy! But as the game got on I never got a GP to found my own religion, other civs beat me to them.
Can I adopt Christianity?, my Religion Points never let me get to GP or even Inquisitor, just missionary (which I get from Holy City to spread Christianity) or the occassional Cathederal

 

[Browd]

Go with the flow. Buy a couple of missionaries and spread the Celtic religion to your other cities and reap the Follower and pantheon benefits. You can't get Founder benefits, but really no one does once the founder has been eliminated.