Recite that which has been revealed to you of the Book and keep up prayer; surely prayer keeps (one) away from indecency and evil, and certainly the remembrance of Allah is greatest, and Allah knows what you do (29:45)

Everything in the universe is consistent. It is the way Allah created it to be. In order for us to maintain consistency and not go astray during our daily lives, we must remember, at fixed times, the one who Created us. On this issue, Allah says

Verily the prayers at fixed hours have been prescribed for the believers (4:103)

We must not underestimate the importance of this obligation. Prayer is addressed directly and indirectly in the Qur'an over 100 times. It is the second pillar of our religion, and it has been agreed upon that one must pray the obligatory 5 prayers each day in order to be Muslim.

"The covenant (which distinguished) between us and them is Prayer, so whoever abandoned it committed an act of disbelief."

It is also reported that a man asked the Prophet (Allah bless him and grant him peace), "What is the best deed?"  The Prophet replied, "Prayer, when it is time."