The disciples stood in great amazement at the rebellion of the angels. 
             Then said Jesus: 'Verily I say unto you, that he who maketh not prayer is more wicked than Satan, and shall suffer greater torments. Because Satan had, before his fall, no example of fearing, nor did God so much as send him any prophet to invite him to repentance: but man-now that all the prophets are come except the messenger of God who shall come after me, because so God willeth, and that I may prepare his way-and man, I say, albeit he have infinite examples of the justice of God, liveth carelessly without any fear, as though there were no God. Even as of such spake the prophet David: "The fool hath said in his heart, there is no God. Therefore are they corrupt and become abominable, without one of them doing good." 
          'Make prayer unceasingly, O my disciples, in order that ye may receive. For he who seeketh findeth, and he who knocketh to him it is opened, and he who asketh receiveth. And in your prayer do not look to much speaking, for God looketh on the heart; as he said through Solomon: "O my servant, give me thine heart. ' Verily I say unto you, as God liveth, the hypocrites make much prayer in every part of the city in order to be seen and held for saints by the multitude: but their heart is full of wickedness, and therefore they do not mean that which they ask. It is needful that thou mean thy prayer if thou wilt that God receive it. Now tell me: who would go to speak to the Roman governor or to Herod, except he first have made up his mind to whom he is going, and what he is going to do? Assuredly none. And if man doeth so in order to speak with man, what ought man to do in order to speak with God, and ask of him mercy for his sins, while thanking him for all that he hath given him? 
           'Verily I say unto you, that very few make true prayer, and therefore Satan hath power over them, because God willeth not those who honour him with their lips: who in the temple ask [with] their lips for mercy, and their heart crieth out for justice. Even as he saith to Isaiah the prophet, saying: "Take away this people that is irksome to me, because with their lips they honour me, but their heart is far from me." Verily I say unto you, that he that goeth to make prayer without consideration mocketh God. 
          'Now who would go to speak to Herod with his back towards him, and before him speak well of Pilate the governor, whom he hateth to the death? Assuredly none. Yet no less doth the man who goeth to make prayer and prepareth not himself. He turneth his back to God and his face to Satan, and speaketh well of him. For in his heart is the love of iniquity, whereof  he huetpeiath not repented. 
         If one having injured thee, should with his lips say to thee, Forgive me and with his hands should strike thee a blow how wouldest thou forgive him? Even so shall God have mercy on those who with their lips say: "Lord, have mercy on us, and with their heart love iniquity and think on fresh sins.' 

  An Islamic Perspective and Commentary
Ishaq Zahid

The foremost act of a Muslim is daily prayer. In fact, Muslims are instructed to pray five times daily at different times during the day and night. In the Holy Quran, God Almighty says,

020.014 "Verily, I am God: There is no god but I: So serve thou Me (only), and establish regular prayer for celebrating My praise."

According to a saying of Prophet Muhammad (peace be on him), prayer is a deciding boundary between Belief and Unbelief. 

The following verses from the Holy Quran describe the expected behavior in prayer and ask for the rememberance of God. There is a strong warning to those who pray to show off.

007.205 And do thou Bring thy Lord to remembrance in thy (very) soul, with humility and in reverence, without loudness in words, in the mornings and evenings; and be not thou of those who are unheedful.

So woe to the worshippers. Who are neglectful of their prayers,  Those who (want but) to be seen (of men), But refuse (to supply) (even) neighbourly needs. (The Quran, 107:4-7)

A believer should submit himself or herself completely in the service of God, as stated below:

Say: "Verily, my Lord hath guided me to a way that is straight,- a religion of right,- the path (trod) by Abraham the true in Faith, and he (certainly) joined not gods with God." Say: "Truly, my prayer and my service of sacrifice, my life and my death, are (all) for God, the Cherisher of the Worlds: No partner hath He: this am I commanded, and I am the first of those who bow to His will. (The Holy Quran, 6:161-163)