How do you deal at a family reunion as an atheist, when 98% of them are all Christian bible thumpers?

I haven't seen most of my family in four years on the East coast, so I am going to our reunion this summer to see everyone. They have this itinerary laid out, with some church service on Sunday (I know I can just not go) and a dinner in the banquet hall of the church. I think it would be tacky if I just showed up to come eat and skip the service, but I am not a Christian, why should I go to the service? Also, I spoke with an uncle about a problem I had, thinking I would get sensible and wizened advice, but I got a lecture on "why don't you believe in god?". Then, my aunt facebooked me, and asked me was I going to church on New Years Day. I was like, nope. Then I caught the spill from her. Now I am being bombarded with calls about my lack of religion from well-meaning family members who are preaching their fire and brimstone speeches at me. "You need to accept god back into your heart for the new year", and "Those kids need to come up in church to learn right from wrong", and "You're following a dark path" and yadda yadda yadda. Right, so I'm just like how do I go here and be cordial and respectful, yet firm in my OWN beliefs (lack of) and right to have that? I'm nearly 30 years old for goodness sake, I believe what I will.