I just can't wrap my head around it

please no judging. I'm very hurt and very confused. last night my ex fiance and I went out to dinner and have a drink. we became friends again January 2017 and it's been up and down. we had an amazing conversation and he kept saying just like this song...if it's meant to be it will be. we went back to his place to get my car and my battery was completely dead. he had to jump start my car and then said you need to come back in and let it charge a little bit because I don't want it to die on your way home. I went back in and I was getting ready to leave I already had my coat on and he pulled me on top of him on the bed and started kissing me. we kissed for a little bit and he asked me if I wanted some dick. I told him I wasn't doing anything that he didn't want and I wasn't pressuring him into any anything. it was good. I love his touch and I love the way he makes me feel. today we met up for lunch because I needed a new battery for my car. as we sat there eating he told me in church today he decided that he was going to dedicate himself to God and that we would no longer be having sex ever again. I don't understand how you make such a drastic decision in less than 12 hours. somebody please make me understand