How should I handle this - break up or make up - What should I do?

My g/f announced to me that she wants to drink alcohol, My beliefs are against this. I've ask her not to, I said I didnt want it in OUR Life because of my beliefs. She used to tell me that she didnt want alcohol She now says I was telling her what she can & can not do by saying I would not be with her & her drinking. I said no it was her choice, she can drink & I can not be around. Well after 10 years of us, to include hearing her tell me how alcohol has hurt / caused problems in her life, she informs me that she is going to start drinking & i again said I 'll be gone. She left to go drinking I dont want to be with out her but My faith, belief, & feeling is Busted. I feel that she doest not care enough for me than to offend me like that. I believe in GOD he is first, & this has made my belief against alcohol stronger as I try (not doing good) live a good life in front of him. I 'd do anything for her, but go against my God & belief What can I say to her - help