In a pluralistic society, we need to transcend these concerns of yours. Birth control. same sex marriage, and kosher should not be a problem if we are understanding and respectful of others. 
Sin is in the eye of the beholder. Others are not bound by your opinion of sin. If you insist on imposing your views then you risk isolating yourself. You will be ignored. The Catholic Church has suffered a similar fate by insisting that their teachings must be obeyed. The days of imposition are past. They must meet their needs of today to be considered and accepted.
You can follow your conscience but it is yours and others have theirs. To find the common ground is paramount to live in harmony with our neighbours.