Believeth (2015)

Sarah moves into her boyfriend's cabin in the woods, where she's shunned by the neighbors until she becomes pregnant. The local pastor and his wife welcome Sarah into their fold, but she can't fit in with the congregation's old-fashioned ways. Soon, Sarah discovers that a strange health disorder has allowed the townspeople to live up to 200 years old, but their obsession with eternal life demands sacrifice - the sacrifice of Sarah's own child.