Elias is--or was--your best friend. He was found and raised in the church just like you, but where you had become an ordinary follower, he had become a holy warrior. A vampire hunter. It was never assured whether he'd come home in the morning, so it wasn't a surprise when he finally didn't. There was a grand memorial held for him--a brave warrior, gone too soon. But no one cared. Not really, anyway. To them, he was just a statistic. You lost your best friend, a person you loved in a way far beyond romantic or platonic love, and they didn't care. It was enough to make anyone lose their faith.
But you didn't. Your god would save him, because Elias was good. He was the best of you all. You never stopped searching. In a way, you were right. Elias was alive. But seeing him crouched over a deer carcass, blood smeared across his mouth, eyes wild, you knew that this was not the work of any god. Elias became the thing he hated most. Elias was a vampire.