It can definitely make things difficult in the long term especially when children are involved. I'm going through a divorce and I told my wife I was atheist before dating. I believe it's best to have as much in common as possible with a partner there won't be a problem finding differences down the road. Compromise will be a necessity but don't compromise your soul. Lol. It's my belief most Christians are to afraid to admit or in denial of being agnostic. I asked myself long ago am I bad because I don't believe?

I Have been agnostic most of my life. I was raised in a rural church. I am now atheist. In my experience I have always given off an amusing smile. I'm polite and unthreatening. It tends to send them off quickly. Sometimes I think that it puts fear in a Cristian to see confidence in an agnostic. It wouldn't hurt for more atheists to be pro-active in a polite manner and not be angry or ashamed. Just speak your mind and be at peace. I still hold Cristian values as it seems logical to me. I just believe this life is all we get.