From the outset, for an act or deed to be considered proper worship, 'ebadah, it must contain two things: (1) Sincerity (Ikhlas). It must be offered simply for the sole purpose of pleasing Allah (SWT) and seeking His pleasure. Allah, said: "And they have been commanded no more than this, to worship Allah offering Him sincere devotion..." (Al-Qur`an 98:5). (2) It must be done by the commands of Allah (SWT) and the practice of the Messenger of Allah (saas); that is what is called obedience (mutaaba'ah). Allah (SWT) states: "Say: if you do love Allah, follow me, Allah will love you and forgive you your sins. For Allah is oft Forgiving, Most Merciful." (Al-Qur`an 3:31)
This verse indicates whoever claims to love Allah without following the commands of the Messenger, claims are lies. To be a true lover of Allah one has to obey, and his deeds must mirror those of the Messenger of Allah (saas). This is why many scholars call this verse the verse of trial because we have been trying to see whether we will obey or not. The Messenger said: "Whoever does a deed without our command, it will be rejected." (Muslim/Bukhari) To achieve the essence of obedience, six points must be considered. I call them the essence of obedience.
(1) REASON (SABABB),
(2) METHOD (KAYFIYYAH),
(3) KIND (JINS),
(4) AMOUNT (QADAR),
(5) PLACE (MAKAAN), and
(6) TIME (ZAMAAN).
The acts of worship are inclusive in one or more of this six essence:
Reason (Sababb)
If you worship Allah for a reason, you must make sure the reason is given or pointed out to you by Allah (SWT) or the Messenger of Allah (saas). It must not be a reason rationalized by you or someone else for you. Hence, regular virtuous acts of Salaat, Fasting, or dhikir will be considered invalid if done for the wrong reasons. For instance, in certain parts of the Muslim world, some Muslims gather together in the month of Rajab to commemorate "Al-Isra Wal Mi'raj", the night journey Prophet Muhammad (saas) took from Makkah to Jerusalem, and from there his ascension to the heavens. This story is in Surah 17 in Al-Qur`an. During this celebration, participants offer Salaat, dhikir, sadaqah as reason, etc. This annual celebration cannot be considered valid because the reason given is not sanctioned by Allah (SWT) or His Messenger.
The Islamic term for acts like these is Bid'ah, or innovation. The question will be, did Allah (SWT) or His Prophet (saas) command us to celebrate Al-Isra ? There is no proof anywhere to be found. Did the Messenger of Allah (saas) know this was a good reason for celebration? If you say he did not know, you have accused him of ignorance. If you say he did know but did not inform us, you are accusing him of cheating, and the Messenger of Allah (saas) is above that. Indeed, Allah (SWT) has described him as being merciful to the believers, and with a keen interest in informing the believers about everything that is good. After all, there is a disagreement among the learned scholars about the month in which "Isra" took place. The most accepted opinion is that it was in Rabee'ul Awwal.
One may ask how would acts of charity, prayer, and dhikir be labeled, bid'ah? You see, these acts in and of themselves are not innovation. What innovation is offering them with unsanctioned reason? Another example, is there are certain Sufi orders who make dhikir, believing that at a certain number the Messenger of Allah (saas) will attend this gathering and bless them. Unfortunately, these people will get nothing from their efforts because of wrong, unsanctioned reasoning.
Method (Kayfiyyah)
This Ummah has been blessed in that Allah (SWT) did not let it wander in the dark as to how to worship Him, or what he liked or disliked about the worship. The methods (kayfiyyah) of acts of worship have been thoroughly described by Allah and His Messenger. He says: "(We sent them) with Clear Signs and Books of divine prophecies, and We have sent down unto thee (also) the Message, that you mayest explain clearly to people what is sent for them, and that they may give thought." (Al-Qur`an, 16:44)
Also, He (SWT) says: "...Nothing have we omitted from the Book..." (Al-Qur`an, 6:38) These two verses indicate if you are looking for the basis for any act, it must be found in Al-Qur`an. If the explanation in Al-Qur'an is not clear enough, the Prophet (SWT) will explain it in his authenticated Sunnah. It follows then that every conceivable act of `ebadah has been detailed in Islamic sources. You are not left to fend for yourself. Thus, no one has the right to make a method, kayfiyyah, of `ebadah on his own, nor should he or she allow anyone else to do it for him, no matter how well versed or respected an individual may be. He may be a Companion, a follower of a Companion, an Imam, or a saint.
For instance, if a Muslim decides to make wudu, ablution, before Salaat, and begins by washing his feet, then face, arms, head, and ears, and winds up with his nose, a complete wudu in terms of thoroughness and amount of washing has been done. But that Wudu is not valid for prayer, because the method, (kayfiyyah) is not correct Because in the method of wudu, sequence (muwaalat) is an important element. Disregarding sequence makes the wudu invalid. Also, let us say a believer thinks the method of cleanliness (taharah) is bathing. So he neglects wudu altogether, thinking he has just finished bathing. His Salaat will not be valid because the only method for cleanliness before Salat is wudu. Allah (SWT) said: "O you who believe! When you prepare for prayer, wash your face and your hands (and arms) to the elbows, rub your heads (with water), and wash your feet to the ankles..." (Al-Qur`an, 5:7)
Kind (Jins)
The kind, jins, of a thing or an act must be by what Allah (SWT) or the Prophet (saas) prescribed. For instance, one of the annual events during the time of 'Eidul-Adhah is the sacrifice of cattle (udhiyah). Cattle are meant camel, cow, lamb, and or goat. If a believer decides to sacrifice the best udhiyah he has for Allah (SWT) and he happens to have a thoroughbred horse worth thousands of dollars and a sheep worth only 85 dollars, and if he decides to sacrifice the horse instead of the sheep, his sacrifice will not be accepted. Although the sacrifice was exceedingly expensive, the horse is not what is asked of him as a sacrifice. It is cattle that he is commanded to sacrifice.
In another example, on the eve of 'Eidul-Fitr, the Lawgiver prescribes food as the medium of Zakatul-Fitr (fast breaking charity) after Ramadan. If an individual decides to give the monetary equivalent, the Zakat will not be valid because the Lawgiver's explicit command is food, not money.
Amount (Qadar)
The amount and number, qadar, for certain acts of worship have already been established by the Lawgiver, such as five times daily prayers, two-and-a-half percent for Zakat, tawaaf (circumambulation) during Hajj or `Umrah, fasting during Ramadan, etc. If the amount is four, two, or three, that is what it should be, no more no less. For instance, if a believer decides to make Zuhr prayer five rakats instead of four, he may have made them most excellently, but five rakats for Zuhr prayer is invalid because the prescribed amount of Raka for Zuhr is four. After all, Maghrib prayer is the only odd-numbered daily prayer, not Zuhr. Similarly, nobody has a right to prescribe for himself or anyone else the amount and number of dhikirs (remembrance of Allah) and tasbeeh (glorification of Allah) without first having the bases for it in Al-Qur'an and or Sunnah.
Place (Makaan)
The place, makaan, for the act of worship to take place must be established by the Lawgiver. No one can concoct a holy place for himself or others without approval from the Lawgiver. For instance, if a believer decides to make I'etikaaf, (the retreat in the Masjid for the sake of worship) in the last ten days of Ramadan, but makes it in his house instead of the Masjid, his I'etikaaf will not be valid because the only place for I'etikaaf is the Masjid. Allah (SWT) said: "...While you are in retreat in the Masjid..." (Al-Qur'an, 2:187) So is the case if a person decides to make tawaaf (circumambulation) around a building instead of Ka'abah, or stand on a mountain other than the plane of 'Arafah, the tawaf and standing will not be valid.
Time (Zamaan)
The time, zamaan, for every act has already been prescribed. For instance, if a believer decides to fast Ramadan in December because it is shorter and a cooler month instead of the ninth lunar month, Ramadan, his or her fasting will not be valid because of the wrong time. Similarly, if he decides to stand on the plain of 'Arafah, but he did so on the tenth day of Dhul-Hijjah, his standing will be like standing on any plain at any time, and religiously valueless.
Therefore, any act that does not correspond with these six virtues, reason, method, kind, amount, place, and time will be labeled an innovation, bid'ah, because Allah says: "...This day have I completed your religion for you, completed my favor upon you, and have chosen for you Islam as your religion." (Al-Qur`an, 5:4)
This verse indicates the religion of Islam is complete and has been perfected. Allah (SWT) uses two words to underscore this fact. Akmaltu, from the rod word "kamula" (complete, perfect), and atmantu from the rod word, "tamma," (completed, finished, perfected and filled up). If the cap is full, can you add anything to it? If you do it will spill, and you may not know whether it is the original that spills or the added one. That spill is the bid'ah. Allah (SWT) is the best knower.