`` deus qui potestate virtutis tuae de nihilo cuncta fecisti ... '' `` oh , god , who by the mighty power didst make all things out of nothing ... '' `` oh , god , who has hallowed wedlock to foreshadow the union of christ with the church ... look in thy mercy upon this , thy handmaid , who is to be joined in wedlock and entreats protection and strength from thee ... '' but how can he show me mercy when i am betraying him ?