Islam does not allow showing off in worship and considers it as a cause of making actions void and useless. It is a kind of shirk (polytheism).
If man’s actions are for the sake of Allah and to show obedience to Him, to be thankful to Him, to come near to His glory, to acquire his mercy and love, or at least, to obtain the reward of the world to come and to be saved from its punishment, they will he correct and fruitful; but if they are for the sake of other than Allah and to get some material benefit, such as fame, importance, status, etc., they will be in vain and will he fruitless.
The Holy Prophet Muhammad (S) was asked: ‘How could one obtain the salvation of the Day of Judgement?’ He (S) answered: “Salvation is that you should not try to deceive Allah; lest He should return your deception to you; for anyone who tries to cheat Allah, will he cheated by Him and He will take the faith away from him. In this case man deceives his own self, and he does not know.”
He (S) was asked again: ‘How does a man try to deceive Allah?’ He (S) answered: “A person performs what Allah has ordered him, but he is concerned about other than Him”.
“Fear Allah in showing off; because it is a kind of shirk (polytheism). On the Day of Judgement he who shows off will be called with four names: O wicked, O disbeliever, O deceitful, O loser, your work came to nothing and your reward was lost. No salvation awaits you. Go and ask the one for whom you have worked for salvation.”
He (S) was asked for the interpretation of “Whoever hopes to meet his Lord, he should do good deeds, and not join any one in the service of his Lord.”1 He (S) said: “Any one who prays to show off is a mushrik; any one who gives alms to show off is a mushrik; any one who fasts to show off is a mushrik; any one who sets out for hajj (pilgrimage) for showing off is a mushrik; any one who performs any duty which Allah has commanded for showing off is a mushrik; and Allah will never accept the work of him who shows off.”
When one obeys other than Allah and disobeys Him, one falls into the shirk (polytheism) through obedience.
Allah the Most High said: “And most of them do not believe in Allah without associating others (with Him).”(12:106) [It means that, they, in spite of their religious faith, obey Satan].
He also said: “And they have taken gods besides Allah that they should be to them a source of strength. By no means! They shall soon deny their worshipping them, and they shall be adversaries to them.”(19:81-82)
He also said: “They have taken their doctors of law and their monks for lords besides Allah.”(9:31)
He also said: “Have you seen him who takes his low desires for his god?”(25:43)
He also said: “Say: ‘O followers of the Book, come to an equitable proposition between us and you that we shall not serve any but Allah and (that) we shall not associate aught with Him, and (that) some of us shall not take others for lords besides Allah;’ but if they turn back, then say: Bear witness that we are Muslims.”
He also said: “Did I not charge you, O children of Adam, that you should not serve Satan? Surely he is your open enemy. And that you should serve Me; this is the right way.”
The Holy Prophet Muhammad (S) said: “No obedience to any creature is allowed when it is a disobedience to the Creator.”
Concerning “And most of them do not believe in Allah without associating (with Him),”2 Imam Muhammad al-Baqir (a.s.) said: “It implies attributing partners in obedience, and not in worship. The sins that people commit are of this category; in this case they obey Satan and make him a partner with Allah in obedience.”
Concerning this Imam Ja’far al-Sadiq (a.s.) said: “It is attributing partners in obedience and not in worship. A man obeys Satan without knowing that; so he becomes a mushrik (polytheist).”
Concerning “And they have taken gods besides Allah, that they should be to them a source of strength. By no means! They shall soon deny their worshipping them, and they shall be adversaries to them,”3 Imam Ja’far al-Sadiq (a.s.) said: “The word ‘Worship’ here does not mean bowing and prostrating for prayer; rather, it is obedience to men. Anyone who obeys a creature and disobeys the Creator actually ‘worships’ him.”
In his epistle to the caliph al-Ma’mun, Imam ‘Ali al-Rida (a.s.) wrote: “To do good to the parents is a religious duty, even if they are disbelievers. But when it is a cause for the disobedience of Allah neither they nor other people should be obeyed. Because no obedience to any creature is allowed when it is a disobedience to the Creator.”
When one is limited in vision and, in the interpretation of each phenomenon, concentrates on its natural causes in a manner which ignores the will of Allah, one falls into this kind of shirk (Polytheism).
Concerning “And most of them do not believe in Allah without associating others (with Him),”4 Imam Muhammad al-Baqir (a.s.) and Imam Ja’far al-Sadiq (a.s.) said: “It is attributing partners unto Him in favours which are given to man.”
Concerning the same ayat, Imam Ja’far al-Sadiq (a.s.) again said: “It is about him who says: ‘If such and such were not there, I or my family would have perished or afflicted by misfortune as you see, he considers a partner for Allah who provides for him and protects him.”
The Imam (a.s.) was asked about phrases like this: “Had not Allah conferred me of His favour through such and such, I or my family would have perished, etc.” He (a.s.) said: “There is no blemish in an expression like this.”
Imam ‘Ali al-Rida (a.s.) said: “That is a kind of shirk (polytheism) which is less than disbelief.”