If you don’t want to suffer government sanctions for refusing to serve same sex couples, how about this: Be open and honest about it. Put it on your window. And on your front door. And on your sign. And in your ads and your Yellow Pages and your facebook. “We support traditional marriage” or something like that should suffice. Be sure it’s prominent.
If you don’t want your employees to use birth control, put it on your door, and on your sign. Put it on your letterhead and mention it in your ads. “We object to birth control” should be fine.
If your beliefs are so deeply held, you should be proud to proclaim them. Don’t hide your light under a bushel. Then you won’t need to worry. The people you don’t like will leave you alone. (The people you do like may leave you alone as well, but that’s a small price to pay for freedom.)