I am an atheist. Was brought up catholic in Ireland but am as atheist as it is possible for one person to be.
At the time of my niece's christening I was also an atheist but much less confident/vocal in my lack of beliefs.
Dsis moved and married abroad in another catholic country. She isn't and never has been religious. Her husband's family are quite traditional. We aren't at all close and I've met DN 3 times since she was born (she's 5). In the event of a terrible tragedy there is no chance in hell (if you believe in that kind of thing) that I would be the caregiver to her kids. Which is sensible and practical and exactly as I'd have it. I'm a stranger to them.
I agreed to be Godmother because a) You don't really say no to these things (old Irish habits die hard) and b) I wanted to improve our relationship.
But ever since it has stuck in my craw.
Standing up in a church and vowing to help raise DN in the catholic faith and having to "renounce the devil and all his evil works" 
was almost physically impossible for me. I, in equal parts, wanted to laugh and walk out.
It really doesn't help that the priest who celebrated the christening (and who I disliked in the same way I dislike all priests) has since been suspended on child abuse charges .
I have no intention of ever voicing these regrets. As explained, it will never be my duty to take over as parent. But I genuinely wish I hadn't gone along with something so repugnant to my own philosophical/moral code. I wish I'd said thanks but no thanks but I'm sure that would've caused more hassle than it was worth?
The sensible thing is to just vent here and never speak of it again isn't it? 