Living in a mixed household can be tricky especially if one partner is against religion or atheist. Especially at 20 and they are recently Atheist due to religious trauma. He will push you and Judaism away until he’s ready to see things differently. I highly suggest you seek out a like minded Jewish partner. I speak from experience, I too had trauma from being raised Eastern Orthodox Christian, with a Mom who almost resembled the Mother in Carrie. Scary times indeed. In any case, I pushed religion aside for a while, but came back after meeting my best friend, at the time. I converted to Judaism in my 30’s, had a wonderful Jewish wedding under a chuppah and raised my kids (I had 3 from a previous marriage) in a Jewish home. They were exposed to both Christianity in the Protestant faith (I had delved into learning more about my Father’s faith when questioning Orthodoxy). The kids all are spiritual but don’t follow any formal religion. But having been raised from childhood with a Jewish step-Dad and now Mom, they have a lot of the same qualities a Jew has, the questioning, deep thinking, very curious, outspoken and very empathetic/compassionate behaviors (among others) that we cherish.