The shulchan aruch rules that if one forgets al hanissim in bentching he should say הרחמן יעשה לנו ניסים ונפלאות כשם שעשית לאבותינו בימים ההם בזמן הזה - Hashem should perform miracles today just as he did in those days. The commentaries wonder - We are normally not allowed to daven for miracles, so why are we supposed to do so on Chanuka?
Answer: Chanuka is a time of emuna in the power of Hashem. If we have such emuna we can daven for miracles. All we have to do is recognize that nature and miracles are the same thing emanating from the same source.
[Klausenberger Rebbe]