Namaz, or prayer, is surrender before God. The Quran says that everything has surrendered before God. The shadow of the tree falls on the ground while the tree remain upright on the ground. 
The Quran says that the tree bows down because it has surrendered. (13.51 Everything in the universe has surrendered before God, but this surrender is not by choice.Everything is completely governed by the law of nature and so there is no other choice for things. 
The tree has no choice other than to let its shadow fall on the ground. Stars have no choice other than to revolve in their orbits. But human beng is the only exception in this universe who surrenders before God while having full freedom. If a person bows down before God, then there is no event greater than this in the whole of the universe. The greatest phenomenon in the entire universe is when a person bows down before God. Surrendering before God while being fully conscious, and accepting that God is the greatest.
Who can do this? This cannot be done by the sun, moon or the galaxy. God You are great. I surrender before You. Only a human being can do this. There is no phenomenon greater than prostration in this entire universe. The price of Paradise is sajdah, or prostration before God. The universe cannot produce anything greater that sajdah, or conscious surrender before God. 
Surrendering before God is a spirit. For example, we must learn to say, I was wrong. This is also a kind of surrender, or sajdah. This is also namaz. The real essence of namaz is to surrender before God, to leave one's ego. 
I often say that in this world the truth represents God. If any matter of truth comes before you, you must surrender. You must say that you accepted it, acknowledged it and surrendered before it.