The meaning of worship (Ibadat) in Arabic lexicon means the utmost limits of humility and modesty, and it is because of this that it is only one who is at the highest level of existence, perfection, and greatness to be worshipped. Thus worshipping anyone other than God is considered shirk, because sincerity (ikhlas) hasn’t been achieved in worship in such a case. Servitude can be summarized into three distinct points:
The first is that the servant should not consider himself the owner of that which God has bestowed upon him by his grace. The servants consider themselves as owning nothing and they consider all property and wealth to be that of Gods, and they place that wealth wherever God has instructed it to be placed.
Secondly, the servant of God does not seek his own benefit nor makes plans for himself.
Thirdly, the servant’s activities are delineated by what God has commanded him and by what God has forbidden him. Through these points, both the reality of servitude can be understood and both the ways of reaching this state. Servitude is the light of ‘Wilayah’ and having the name of a servant is the best of names. The complete and perfect human being is the ‘Slave of God’ (Abdullah), who is entirely annihilated in God and overcome by his divine names.
Therefore, the servant of God is an individual who views the obedience of God’s commands and his love to be a pleasure. This servant asks God of his needs, tells him of his problems, and trusts and relies on God for everything.
The meaning of worship (Ibadat) in Arabic lexicon means the utmost limits of humility and modesty, and it is because of this that it is only one who is at the highest level of existence, perfection, and greatness to be worshipped. Thus worshipping anyone other than God is considered shirk, because sincerity (ikhlas) hasn’t been achieved in worship in such a case.
Worship has three different grades: some worship God in hope of the reward of the hereafter and due to fear from punishment; these are the general masses of the believers. Some others worship God due the honor of worship and in order that God considers them as his servants. Still others worship God due to his greatness and majesty, and this is the final and highest stage of worship.
According to Imam Sadiq (a): the word Abd is derived from three letters (ع - ب - د). The Ain alludes to the knowledge and certainty of a servant in relation to God, the most High. The Ba refers to the separation and distance of him from everything besides God. The Dal denotes the closeness and proximity of the servant towards his creator, without any veils or intermediaries.
The servant, in spite of all of his perfections and virtues, considers himself completely indebted to his lord. Therefore, he submits himself completely to his lord, and this very essence of considering himself as nothing and ignoring his own wishes and desires, brings him nearer to his creator. This continues until it reaches a point where the Prophet (s) has described as such: The true servant of God is one who considers his obedience as a sweetness and considers the love of God as a pleasure. He asks God of his needs, tells him of his problems, and trusts and relies on God for everything.
What is Servitude?
Imam Sadiq (a) says: The reality of servitude is in three things. Firstly, the servant should not consider himself the owner of that which God has bestowed upon him. The servants consider themselves as owning nothing and they consider all property and wealth to be that of Gods, and they place that wealth wherever God has instructed it to be placed.
Secondly, the servant of God does not seek his own benefit nor makes plans for himself.
Thirdly, the servant’s activities are delineated by what God has commanded him and by what God has forbidden him. Therefore, if the servant does not consider himself the owner of what God has given to him, then giving charity in the way of God will be very easy for him. And since the servant of God has given over the management of his affairs to God, then the calamities and difficulties of the world will become easy for him. And when he occupies himself with what God has ordered…then he will not find the opportunity for ostentation or pride. Therefore, if an individual follows these three instructions, then his interactions with Satan and the people will be very easy. This individual will not seek to amass worldly wealth, nor will he seek glory or act pridefully amongst the people. If he sees that people possess certain things in regards to worldly position or wealth, he will not desire that for himself in order to supposedly raise his own rank (in the eyes of the people); in conclusion, his days will not be spent and wasted and vain endeavors. 
Servitude is the key to ‘Wilayah’, and being called by the name of a servant is one of the best names. This is why the honored Prophet (s) of Islam was the true ‘Abdullah’ (servant of God) and during the night of the ‘Miraj’, he requested the status of being a servant (of God): (أضفنى إلیک بالعبودیة یا ربّ)
It has been narrated from Abu Baseer that Imam Baqir (a) said: From amongst the supplications of Amirul Mumineen (a) was the following: Oh my Lord, it is enough of an honor for me that I am your servant, and it is enough of a glory for me that you are my Lord. Oh my Lord, in the same way that I am happy that you are mine, therefore make me successful in that which you like.
The complete human being is the Abdullah (the slave of God), and he reflects all of the manifestations of the names of God. He is ‘melted’ in the divine being, and overcome by the divine names. How beautiful is the saying of Khajah Abdullah Ansari who said: “O Lord! If you call me once by the name of “My Servant”, the sound of my laughter (out of joy) will be heard across your arsh (throne)!”
In a Qudsi tradition it has been narrated that: Oh servant of mine, obey me so that I can make you like me; I say to a thing “be” and it is. You can say to a thing “be” and it will be. According to Imam Sadiq (a): ‘"العبودیة جوهرة کنهها الربوبیّة"’, which means that the servitude of God the Most High is a reality and essence whose inner dimension is Rububiyyah (lordship). Through the medium of servitude, the human spirit becomes unburdened and light and becomes capable of reflecting divine light. As it becomes more purified and light, it likewise becomes more and more capable of more accurate divine reflections, and the true divine nature gradually becomes more apparent, to the extent that all of the individual’s potentials to be a vicegerent of Allah reach actuality, and he becomes the Khalifatullah (vicegerent of God) in all the worlds of existence. It must be known that this is not a way of becoming deity, but is a way of becoming a true representative of God, through which the divine nature is manifested. It is necessary to mention that the Khalifatullah (representative/vicegerent of God) does not perform divine actions himself, but that God manifests his actions through that individual’s medium; in essence, that individual is used as a window through which the divine manifests his divine names and characteristics. Therefore, the one who knows God (the Aref) is an individual who reflects all of the eternal beauty and majesty of God. In all of the grades of the miracles of the Prophets (a), Imams (a), and Awliyaa’, God is in reality the one who is performing those miracles, and the ‘self’ of the ‘Friend of God’ is completely melted in God, and this is the rank of servitude. This is that rank that is found as a result of obedience to God the Most High. When the seeker is in this rank, he sees himself as the "اسم الله", "علامة الله" , and "فانى فى الله", which mean the name of God, the sign of God, and the annihilated in God. In addition, he sees all of the other creations in this same manner, and if he reaches a high enough stage, he will become the true Abdullah, or slave of God. The reason why the word slave (Abd) is used in the noble verse (سبحان الذى اسرى بعبده), which means ‘Glory to (Allah) who did take His servant for a journey by night’ can be because the ascent to the nearness of God is only possible through servitude and obedience and need and cleansing oneself of the filth of selfism and independence; [it is because of this that] one bears witness to the prophethood of the prophet only after he has bore witness to his being a servant of Allah in the tashahud of the prayer, the reason being that servitude is the ladder of prophethood an in prayer, which is the ascension of the believer and the manifestation of the ascent of prophethood, it begins with the removal of all veils with Bismillah, which is the very essence of servitude, “سبحان الّذى اسرى بِنبیّه بمرقاة العبودیة المطلقة”, therefore, [what is meant is] Glory to the one who did take his prophet on a journey with the ladder of absolute servitude and absorbed him through the means of servitude and freed him of the realms of Mulk, Malakut, Jabarut and Lahut and took the rest of His servants who were under his auspices and have a share of the names of Allah and…to the miraj of nearness to Him.
The Role of Intention and Ikhlas (sincerity in intention) in Worship
In the view of the common people, intention is taken to mean an intention towards obedience whether out of fear or want: (یدعون ربهّم خوفاً و طمعاً) According to the view of those with inner knowledge (Marifah), intention is taken to mean an intention towards obedience out of glorification and majesty: (فاعبد ربّک کانّک تراه و ان لم تکن تراه فانّه یراک). Amongst the people of love (Jazbeh and Muhibbat), it means an intention towards obedience, out of love and longing… Amongst the Awliyah (the friends of God), it means an intention towards obedience in subordinance or otherwise, after viewing the majesty of God independently and essentially and annihilation in the existence of God essentially and in quality and action. And one of the most important conditions of the intention is its purity.
In the worship of the common people, purity of intention means to free it of all shirk, hidden and evident, which manifest in the likes of riya, ujb and pride in one’s worship: “الا لله الدین الخالص” Look! Only pure faith is worthy of Allah. And in the worship of the elite, it means for one to free it of all want (of desires) and fear (of punishment), all of which are seen as manifestations of shirk in their method. For the “Companions of the Heart” (i.e., the lovers), it means to free it of any traces of selfism which is considered the great shirk and great kufr in the eyes of the arefs. In the worship of those who have reached the highest levels, it means to free it of all ru’yah ubudiyyah and ibadah, and even ru’yah kown, as Imam Khomeini says: “The sound heart is the one who meets its lord and there is no one other than Him in it.”
 Imam Khomeini, Asraar al-Salah; Parvaz Dar Malakut, Farsi translation, Fahri, Seyed Ahmad, vol. 2, pg. 190.
 Nahjul-Balaghah, saying 237; Usul Kafi, vol. 2, pg. 84, hadith 5.
 Damadi, Seyed Mohammad, Sharh bar Maqamaate Arba’in, pg. 125.
 Misbah al-Shariah, chapter 100.
 Sheikh Bahai, Muhammad, Arba’in.
 Majlisi, Bihar al-Anwar, ‘hurufi’ print, Heydari Publications, vol. 1, pg. 224, hadith 17.
 Allamah Tabatabai, Muhammad Husein, Tafsir al-Mizan, vol. 1, pg. 277.
 Bihar al-Anwar al-Jaami’ah li Durar Akhbaar al-A’immah al-At’haar, vol. 74, pg. 402; Al-Hikam al-Zaahirah, translated by Ansari, pg. 488, hadith 1352.
 Shirazi, Seyed Hasan, Kalimatullah, pg. 140, number 154.
 Muhammadi Rey Shahri, Mizan al-Hikmah, vol. 6, hadith 11317.
 Huseini Tehrani, Seyed Muhammad Husein, Anwaar al-Malakut, vol. 1, pg. 288.
 Imam Khomeini, Sirr al-Salah, The Institute for the Compilation and Publication of Imam’s Works, pg. 89.
 Imam Khomeini, Sirr al-Salah, The Institute for the Compilation and Publication of Imam’s Works, pp. 75 and 76.
 Mowlawi, Jalaluddin Muhammd , Mathnawi Ma’nawi, first chapter, pg. 22.
 Imam Khomeini, Sirr al-Salah, pg. 75.