I can see both sides, believe it or not. ... or maybe more?

One problem is this: conservative Christians don't believe you can be a good person apart from God. Plus, it is a core belief of Americans that children need (yes, need for their own psycho-social-spiritual growth) to have at least a child's understanding of God. You were given that opportunity, why deny your daughter of it?

I think that now that you are older and have good questions that it is the perfect time for you to attend church and ask all those questions of people other than your parents! You don't have to go to the church your parents attend, or even go to just one church... but since you have your own doubts, you need to get them settled for your own health, imo.

Now... one way you can "get your folks off your back" is to have a plan for finding truth, and present it to them.