I have been confused and crying for the past 15 hours because my stepfather bullied me, and declared me evil.

I am a 19 yo agnostic atheist female, in a family of Christians. My whole life I have always questioned god, and with the help of my SO, I have gladly really questioned my surroundings. Whenever I am around my family I never say much when they talk about the church or god, as to not offend...and it is their right and beliefs.

Recently after reading a lot about extreme Christians on r/atheism, I decided to email my mom some innocent questions that I wanted to be answered from a less extreme view. These were questions about her opinion with the "war on religion" and evolution. Along with why anyone who believes different must have a vast amount of proof for it to be deemed true in their eyes.

I went to my moms house yesterday with my SO. She innocently handed me a book, calmly explaining how it is about an atheist who traveled the world disproving god, when he only proved god to himself by doing so. Knowing I would think the book is BS, I took it and will read it, because I like to be well informed on all view points. My mom and I were calmly discussing small things like where her belief in god came from...ect.

Then came my step father. He started over powering the conversation saying he was evil and wanted to only hurt when he was an atheist. I thought to myself, "is this really happening" while he said this country was founded on Christianity because the people who came here were Christians escaping persecution. He said it clearly states this is a christian nation in the constitution, that god was real in egyptian history, and that a Muslim or Buddhist could pray aloud at his work, but not Christians. I tried to get a word in but he only got louder and more ignorant by yelling at me, telling me how humans don't know right from wrong without god. He said darwin was quoted stating his own theory was wrong...how even Einstein believed in god....basically all of the classic arguments a Christian believes from being told. I was upset because he wouldn't let me talk...and I would've let him finish until he pointed at me yelling you are born evil, and you don't know right and wrong without god. At this point I went on a rant I can't rememeber (which my SO said was surprisingly coherent) about how much that hurt me, how I don't think I should govern another, etc. I then ran off and left....and preceded to break down and cry for the past 15 hours. I don't know why this hurt me so much....but it really did. His ignorance is sickening.

My question to you is, how do I make a coherent argument against his "facts?" I know I can't change them...but my mom and brother are almost controlled by his ignorance...and I want them to know the proof he hides. Has any one else had this experience? I really feel abandoned and broken at the moment.

Even if all I get are critisisms, I welcome every ones advice.

EDIT: Thank you r/atheism for being so supportive! I have been reading r/atheism for almost 2 years without saying a word. I LOVE seeing rational thinking in the world, even if it has to be in front of a computer screen.**