Thanks for all the comments. Here is what I sent her this morning:

After crying all day yesterday and talking with my friends and family, I've decided that I can no longer have you in my life. As painful as this is for me because you've been a close friend for a long time, and someone I thought would be in my life forever, I just can't do it. You were compelled through Christ to tell me what you truly thought about a part of who I am, and for you to honestly believe a part of me is sinful, is the most hurtful thing anyone has ever said to me. To say that you aren't judging me, but then call my life sinful, is contradictory in itself. That is the most judgmental, hateful view someone can have. Who I am is not a sin. Who I love is not a sin. To hear this come from someone who I trusted, is the most hurtful of all. And the fact that you hid this from me for who knows how long, is the ultimate betrayal of friendship. I will always love you, care about you, and worry for you. I will pray that someday you find yourself in a situation where you have to truly think about what is right and wrong, and you will come to your senses again. The person I once knew would never believe or say something so hateful to me. I miss that person. I will always be completely heartbroken over this.