Yes it is about someone who has lost the love of his life. Something which has sustained him and been a huge comforting presence since childhood,and now he is coming to realise that he can no longer accept
its teachings and it's hurting. 'I could never go with you no matter how I wanted to.' It's his Christian faith that he has lost, and there is an emptiness there 'I turn to face an empty space where you used to lie',and it saddens him. Thats how I would feel anyway.