My g/f's dad Dislikes me!!!!?

My g/f took me to meet her dad, which turned out that he is a hard core bible thumper, she told him that I am atheist and to not preach the "word" to me lol....but he does not like me cause I have tattoos all over my body and cause I'm atheist, but I treat his daughter with proper respect and treat her good its not like I'm a lo life...I graduated high school and college and I make $40k a year I own my house car and I'm only 23, I just want to know what can I do to gain his respect....thank u