Like thankfulness such recitation is a duty of servanthood to be performed both verbally and actively and also with one's heart and other faculties of conscience. Verbal recitation ranges from mentioning God Almighty with all His Beautiful Names and sacred Attributes; praising exalting and glorifying Him; proclaiming one's helplessness and destitution before Him in prayer and supplication; reciting and following His Book (the Qur'an); and voicing His signs in nature and the seal special to Him on each thing and event.
Recitation by the faculties of conscience primarily the heart consists of reflecting on the proofs of His Existence and Unity and His Names and Attributes radiating in the book of creation (the universe); meditating on His orders and prohibitions. His promises and threats and the reward and punishment issuing from His Lordship to design or order our lives; and trying to penetrate the mysteries behind the veil of visible existence by studying creation and following certain spiritual disciplines. In addition one repeatedly observes the heavenly beauties manifested as a result of such instances of penetration; and thinks that whatever exists in the universe pulses with messages from the high empyrean world manifesting the meaning of the invisible world and functioning as a window upon the Truth of Truths.
Those who feel this constant pulsing existence hear the invisible world speaking eloquently and observe the manifestations of Grace and Majesty through those windows are so enraptured with such unimaginable spiritual pleasure that one hour spent with such pleasure is equal to hundreds of years spent without it. As a result they advance along their way to eternity lost in Divine gifts and spiritual delight. When the one reciting feels the light of His Glorified Face surrounding all existence he or she is rewarded with the sight of indescribable scenes and becoming aware of all other beings reciting God's Names in its own tongue begins to mention Him with many of His Names.
Reciting God's Names sometimes causes the reciter to enter a trance-like state in which one's self is lost. Those who enter this entranced state or ecstatic contemplation utter such phrases as: There is no existent save He. There is nothing seen save He and There is no god but God. There are others who meaning and keeping in mind all Divine Names according to the inclusiveness of their consciousness pronounce only save God and continue to declare His Unity. These seconds spent in this atmosphere of nearness to God and His company the seconds of light and radiance are much happier and more rewarding with respect to eternal life (in the Hereafter) than years spent with no light. This is what is referred to in a saying attributed to the Prophet upon him be peace and blessings: I have a time with my God when neither any angel nearest to God nor any Prophet sent as Messenger can compete with me. 
Active or bodily recitation consists in practicing religion with utmost care enthusiastically performing all obligations and consciously refraining from all prohibitions. Verbal profundity and awareness largely depend on active recitation which also means knocking on the door of Divinity searching for admittance proclaiming one's helplessness and destitution and taking refuge in Divine Power and Wealth.
One who regularly and intensively mentions God or recites one or some of His Names is taken under His protection and supported by Him as if having made a contract with Him. The verse: Remember and mention Me and I will remember and mention you (2:152) expresses this degree of recitation by which one's innate destitution becomes the source of wealth and helplessness the source of power. This verse also means that one's regular remembrance and worship of God will result in His bestowal of favors and bounties.
Invoking and calling upon Him bring forth His favors. One who remembers Him even while going about his or her daily affairs and preoccupations will find all obstacles removed in both this world and the next. His company will always be felt and He will befriend one left alone and in need of friendship. If one remembers and mentions Him during times of ease and comfort. His Mercy will reach one during times of trouble and pain. Those who struggle in His way to spread His Name will be saved from humiliation in both this world and the Hereafter. Such sincere endeavors will be rewarded with special favors and ranks that one cannot now imagine.
The desire to mention Him and recite His Names will be rewarded with Divine help so that such activities can continue and guidance can be increased. The continuation of the second part of the above verse (2:152) that is: Give thanks to Me and do not show ingratitude to Me suggests a virtuous circle in which a believer passes from recitation to thankfulness and from thankfulness to recitation.
Recitation is the essence of all types or acts of worship and the origin of this essence is the Qur'an. Then come the luminous celebrated words of the Prophet to whom the Islamic Shari'a was sent. All recitation whether audible or silent attracts and embodies the manifestations of the light of God's Glorified "Face." It also denotes proclaiming God to all human beings and jinn and spreading His Name throughout the world in order to show one's thankfulness for His manifest and hidden favors. When there is almost no one left to proclaim His Name existence will be meaningless. According to the Prophet upon him be peace and blessings the universe's total destruction will take place when there exist almost no people to proclaim His Name. 
Recitation irrespective of its style is the safest and soundest way leading to God. Without it it is difficult to reach God. When the traveler remembers Him in his or her conscience and puts this remembrance into words with his or her tongue and other faculties an inexhaustible source of support and (spiritual) provision is tapped.
Recitation signifies a journey toward Him. When one starts to mention Him or recites His Names both verbally and through feelings and actions as well as in one's heart as a chorus one enters a mysterious lift ascending to the realm where spirits fly. Through the slightly opened doors of the heavens indescribable scenes are beheld.
There is not a specific time for reciting God's Names. Although the five prescribed daily prayers the chief act of worship are performed at the five appointed times and cannot be performed at certain times (e.g. during sunrise and sunset and when the Sun is at zenith at noon) a believer can mention God and recite His Names whenever he or she wishes: They mention God standing sitting and lying down (3:190). There is no restriction of time or manner on reciting God's Names.
It is hard to find in the Qur'an the Sunna and the books of the early righteous scholars anything more strongly recommended than the recitation God's Names. From daily prayers to holy struggle in His way it is like the soul or blood of all worship. The profundity of recitation is proportional to the depth of feeling for God. Sufis call this "peace of heart" or" witnessing."
Some mention God Almighty and reach Him in their hearts by a mysterious way; others know Him by their conscience and feel His constant company by means of the point of reliance upon Him and seeking His help in their inner worlds. Since they remember Him uninterruptedly always mention Him with their heart and conscience always feel Him in their being and live fully aware of His constant Presence they regard mentioning Him (verbally) as heedlessness and ignorance of Him. One who has reached this degree of dhikr says: God knows that I do not remember Him to mention Him just now. How should I remember and mention Him now seeing that I have never forgotten Him?
 Al-'Ajluni. Kashf al-Khafa'. 2:173.
 Muslim. "Iman." 234.
 Muslim. "Iman." 234.