The power of suratul fatiha, know what you are saying when you are praying.

Hadith Qudsi - 8

A prayer performed by someone who has not recited the Essence of the Quran during it is deficient (and he repeated the word three times), incomplete. Someone said to Abu Hurayrah: [Even though] we are behind the imam? He said: Recite it to yourself, for I have heard the Prophet (may the blessings and peace of Allah be up on him) say: Allah (mighty and sublime be He), had said: I have divided prayer between Myself and My servant into two halves, and
My servant shall have what he has asked for. When the servant says: Al-hamdu lillahi rabbi l-alamin, Allah (mighty and sublime be He) says: My servant has praised Me. And when he says: Ar-rahmani r-rahim, Allah (mighty and sublime be He) says: My servant has extolled Me, and when he says: Maliki yawmi d-din, Allah says: My servant has glorified Me - and on one occasion He said: My servant has submitted to My power. And when he says: Iyyaka na budu wa iyyaka nasta in, He says: This is between Me and My servant, and My servant shall have what he has asked for. And when he says: Ihdina s-sirata l- mustaqim, siratal ladhina an amta alayhim ghayril-maghdubi alayhim wa la d-dallin, He says: This is for My servant, and My servant shall have what he has asked for.