As for your example, if I married a Jew (and I dated one directly before my husband actually) I don't see at all why his Judaism would trump my atheism! Our children would belong to both of us, not just him. I'd let them have dinners but no way would I indoctrinate them. Religion should be their choice. There is a big difference between telling your child "I believe this, others believe that" and teaching religion as fact.
Atheism is not a religion, it is generally a belief in facts, evidence, science, reason. It is, however, no less strong because it isn't based around a "god" who has never been seen, heard or otherwise reliably documented ever. My atheism is just as important to me as your religion might be to you, perhaps even more so. Please don't be so dismissive of something I don't think you actually understand (based on your post here).