In order to achieve faith's perfection and attaining higher spiritual positions of God's Remembrances (Dhikr), Witnessing, (Shahood), and Countenance (Laqa), the following means should be utilized:
19.1. Meditation and Reasoning
The reasons and arguments presented for the proof of God's Existence might be of some help in this regard, because, the reasons presented in the Holy Quran and other books of wisdom and gnosticism confirm that all the worldly phenomenon are needy and deprived rather in their essence are absolute indigence and deprivation. In order to exist, and for continuation of their actions and movements they all are related to a - "Free from Want Existence", rather in essence are related and dependent upon Him. All are needy and limited.
In the entire circle of existence there does not exist more than one -"Free from Want", Self Sufficient and Infinite Existence and that is the Essence of Self Existent (Wajib al-Wajood), Whose Existence is absolutely free from defects, limitations, and needs. He is the Source of all Perfection Whose Power, Knowledge, Life, and Other Characteristics are Absolute and Infinite; is present everywhere and is the overseer of all things, nothing is hidden from Him, is closer to all the creatures, even is nearer to man than his jugular vein. The Quranic verses and traditions have explain this in detail. Following are some examples:
"To God belong the east and the west: Withersoever ye turn, there is the presence of God.”
-the Holy Quran (2:115)
“And He is with you wheresoever ye may be. And God sees well as that ye do."
-the Holy Quran (57: 4)
"We are nearer to him than (his) jugular vein."
-the Holy Quran (50:16)
"For God is witness of all things."
-the Holy Quran (22:17)
Therefore, pondering and reasoning over the Divine proofs helps man's exit from the intense darkness of unbelief, makes him enter inside the boundaries of faith, opens the path of perfection, and invites him towards action which is the pre-requisite of belief.
19.2. Deliberations over the Quranic Verses
The Holy Quran regards all worldly phenomenon as sign and indications of the existence of the World's Creator. The Quranic verses emphasize repeatedly to deliberate and think about God's signs, and the beauties, wonders, rhythm, and coordination which is controlling them in order to discover the existence of a Learned, Wise and Omnipotent God.
The human beings have been asked to deliberate deeply about their own creation, mysteries, and wonders incorporated within the structures of their sprit and body, the differences of colors and languages, and the crea1tion of their spouses. Similarly, they are asked to ponder about the creation of sun, moon, stars, and their wonderful movement. Further they are encouraged to look and think about the creation of earth, mountains, hills, trees, plants, and animals living inside, the water and over land. Also, the Holy Quran has described a lot of examples from these creations.
The world indeed is beautiful and fascinating, arid a little bit pondering would reveal hundreds of hidden wonders and mysteries within its creatures. Starting from sun, mo6n, stars, milky ways, and clouds till the fascinating and mysterious world of atom; from the great forests till different types of plants and smaller and larger trees; from the great animals like elephant and camel till the tiny ants, mosquitoes, bacteria, and viruses all of them reveal a special beauty and elegance.
By witnessing the wonders of these worldly phenomenon and the most accurate precise coordination prevailing upon them, a human being may discover the Infinite Grandeur, Majesty, Wisdom, and Knowledge of the Creator and, thus, becomes astonished and fascinated crying from the inner depths of this heart:
"Our Lord! Thou createdst not this in vain.”
--the Holy Quran (3:191)
Look at the brightening sky full of stars and deliberate deeply over their creation; sit near the edge of a forest and see the Majesty and splendor of God-Almighty. Alas! The world is so beautiful !!
After being blessed with faith (iman) and enlightenment (marefah) a human being must strive and endeavor to perform righteous deed and must discharge his religious obligations. Because, it is through the performance of righteous deeds that the belief and enlightenment achieve perfection, ultimately ascending towards God's Nearness. It is True that belief, enlightenment and the words of purity (Monotheism) ascend towards Him, but in this movement they are assisted by the righteous deeds. The God-Almighty said in Holy Quran:
"Whoso desireth power (should knew that) all power belongth to God. Unto Him good words ascend, and the pious deed doth He exalt."
-the Holy Quran (35:10)
The righteous deeds may be compared to the fuel in an airplane. So for it contains fuel it may continue to ascend, but the moment its fuel is finished it crashes immediately. Likewise, belief, ,and enlightenment so for are accompanied by righteous deeds they help ascend the human being towards Upper Heavens, but without the assistance of righteous deeds a human being crashes like an airplane without fuel. God-Almighty said in the Holy Quran:
"And serve thy Lord till the inevitable cometh into thee."
-the Holy Quran (15:99)
The only way for achieving self-perfection and attaining the state of certainty (yaqeen) is to strive seriously to discharge obligations, worshipping, and servitude of God-Almighty. If some one imagines that he may attain exalted spiritual position through means other than worship -is in gross error.  If God willing (inshaAllah) the discussions regarding righteous deeds will be continued later on.
19.4. Invocations and Supplications
Islam, especially has emphasized the importance of continuous recital of invocations and in this regard special invocations and supplications have been prescribed by the Holy Prophet (S) and Infallible Imams (A) whose recital earns a special reward. Invocation in Islam is considered as a type of worship which helps one to achieve self-perfection and God's Nearness. For example The Holy Prophet (S) had said:
"There are five things which makes a human being's deeds heavier: Glory to God (Subhan Allahi), All praises belong to God (AlhamduLillahi), there is no God but god (La ilahi-illallahu), God is Great (Allahu Akbar) and to remain patient at the demise of a righteous offspring."
-Bihar al-Anwar, vol. 93, p-169.
"When on the Night of-Ascent (Mairaj) I was taken into the paradise I saw the angels busy in building the palaces of silver and gold but occasionally they suspended the work. I asked them: 'Why do you work intermittently?' 'When we do have construction material, we continue work but when the material is consumed we are forced to terminate the work.’ Replied the angels.”
“What sort of material you require ? I asked. "Glory to God," "All praises belong to God", "There is no god but God" and "God is Great"; when a believer is busy in invocation -we receive the material and start to build, but when he forgets to offer invocation, we too are forced to terminate the work.” Replied the angels."
-Bihar al-Anwar, vol. 93, p-169.
The Holy Prophet (S) said:
"Whoever recites: "Glory to God", a tree is planted for him in the Paradise, similarly God-Almighty orders plantation of a tree for a believer inside the Paradise for each recital of" All praises belong to God” or “There is no god but God or “God is Great". "Then a Qureshite man asked: 'Oh Prophet of God! Then we will have plenty of trees in the paradise.
'Yes it is so! But be careful not to send the fire which will bur" all the trees, because God-Almighty had said in the Holy Quran: O Ye who believe! Obey God and obey the Messenger and render not your actions vain. ' Replied the Holy Prophet (S)."
-Bihar al-Anwar, vol. 93, p-168.
Each phrase which induces God 's Remembrance in a human being and whose meanings are related to praise, supplication, and adoration of God-Almighty -is called invocation (dhikr). But traditions have prescribed special invocations whose recital brings special rewards. Some of the important invocations are as follows:
(La ilahi illallahu)
“There is no god but God.”
“Glory to God"
(Al hamdu lillahi)
"All praises belong to God."
(La hol wala quwwateh illa billah)
"There is no power except God-Almighty."
(Hasbanallahi wa nemal wakil)
"God is sufficient and He the best defence.”
(La illahi illallahu subhanak inni kuntu min al zalimin)
"There is no God save Thee. Be thou Glorified. Lo! I have been a wrong Doer."
(Ya hayyu ya qayoom ya min la ilahi illa unt)
"Oh Self-Existent, Eternal these is no God except Thee."
(Afwaz amri illallahi innalahi basir bil ibad)
"Leave the affairs to God, He is aware and knowledgeable about His servants."
(La howlwala quwwateh illa billah il 'ali ul azim)
"There is no power except God the Exalted."
(Ya arhamar rahimin)
"Oh! The Merciful and Compassionate."
(Ya zul jalale wal Ikram)
"Oh! The Majestic and Magnanimous."
(Ya ghani ya mughni)
"Oh! Thou Who is free from needs, and oh! Thou Who is the Granter of our needs."
Similarly there are other Holy attributes of God-Almighty which have; been mentioned in the traditions and supplications. All of them are invocations, motivates a man towards God's Remembrance, and. are means of His-Nearness.
A wayfarer may select any one of the above mentioned invocations and should recite them continuously. But some enlightened gnostics preferred certain special invocations. some of them recommended: "there is no god but God" (La ilahi illallahu), while others selected: "glory to God" all praises belong to God; there is no god but God; and God is Great; (Subhan allahi, wal hamadu lillahi wala ilahi illallahu walahu akbar).
But according to some traditions it may be concluded that the invocation: "there is no god but God " " (La ilahi illallahu) " possesses distinction over other invocations. The Holy Prophet (S) had said:
"The best worships are the recital of invocation ‘there is no god but God.’"
-Bihar al-Anwar, vol. 93, p-195.
"The phrase -"there is no god but God " -is the chief and most distinguished among all other phrases of invocations."
-Bihar al-Anwar, vol. 93, p-204.
The Holy Prophet (S) had narrated from Arch Angel Gabriel that God-Almighty said:
"The phrase -There is no god but God -is the most stable shelter of Mine. Whoever entered in it shall be immune from My Punishment”
-Bihar al-Anwar, vol. 93 p-192.
Since the aim of invocation is attention towards God-Almighty, therefore, it may be concluded -that every phrase which improves and increases a person's motivation to remember God-Almighty is indeed the most suitable invocation for that person.
Generally speaking individuals, conditions and their spiritual ranks differ. It is quite possible that the phrase "Oh! God" (Ya Allah!) under certain conditions might be interesting and suitable for some one, while the phrase- "Oh Thou the Granter of the prayers of the depressed." (Ya Muji bud dawatul Muztarin) may suit some other individual. For some individuals the phrase -"there is no god but God. " (La illahi illallahu) may suit, while for some others the phrase- "Oh Merciful", Concealer of faults" (Ya Ghafar! Ya Sattar!) might be more suitable, and similar is the case with other invocations.
It is because of these considerations that if a wayfarer has access to perfect teacher, it would be better for him to seek his guidance in this regard. But if one does not bas access to such learned teachers he may resort to supplication books, traditions and guidelines left by the Holy Prophet traditions and guidelines left by the Holy Prophet (S) and Infallible Imams (A) of Prophets (Ahlul Bayt).
All invocations and worships are good and if performed correctly may help a wayfarer to attain higher gnostic stations. A wayfarer might utilize some or all of them but the learned teachers of gnostics recommend that in order to attain the positions of invocation (dhikr) and witnessing (shahud), a wayfarer must select a special invocation and then must undertake its recital for a certain fixed numbers in a special manner in order to accomplish the desired goal.
Here it is important to point out that invocations and supplication prescribed in the religious law, although are worships and could be a means of achieving God's Nearness but, their main aim is attaining the stage of absolute cut off from other than God, and absolute attention and heart's presence towards God-Almighty. Therefore, simply recital of phrases without paying attention towards their meanings and remaining negligent towards the real aims behind them would not produce any result. Because, recital of invocations and even their continuous repetition is not so difficult but this action alone may not help a wayfarer attaining his cherished goal.
What is useful is concentration and heart's presence towards God-Almighty, and negation and complete cut off from every thing other than Him, which is extremely difficult. So far as one does not achieve negation of others than God, he does not attain the worthiness and decency of receiving God's blessings and illuminations. Only a heart absolutely and thoroughly cleansed from all existence other than God -has the honor of becoming a sacred place for the illumination of Divine light. Attaining concentration of thoughts and negation of things other than God require !' serious decision, perseverance, supervision, and constancy. It is not so that one will achieve it during the first attempt without practice and undertaking exercises. We must treat the self cautiously and should make him habitual of this act gradually.
 According to a tradition narrated by Imam 'Ali bin al-Hussein (A), since God was aware that the later period of history, would produce curious people, and therefore: He revealed the verses of Surah Iron till verse "knower of all that is in the breasts, " in order to define the boundaries for investigating His essence and characteristics. Therefore whosoever has allowed himself to ponder over beyond these prescribed limits is bound to be doomed.
As if the Surah al Ikhlas, "Say God is One" says to the prayer offerer: God is unique Supreme Power, the Most High, Exalted, the Needless, His essence beyond description, neither Begets nor Begotten, and there is no one similar to Him or His equivalent. Learned, Seer, Wise etc., and other characteristics of God's essence whose knowledge and awareness is obligatory for Muslims, and are regarded influential and effective in shaping their lives, and ascension of their spirits, have been repeated in other surahs of the Holy Quran. Do not think beyond the limits as already defined in this surah about God's essence and know-how about His characteristics. Rather, concentration should be exerted for performing deeds, which would eventually enlighten the believer in knowing God better . Do not think that by engaging in lengthy mental debates about His essence you will achieve more enlightenment. It is not so! Instead, try to. achieve this desired enlightenment by bringing purification and spirituality to your inner self, and by practicing the principles of Monotheism in your deeds and action; and that is the way the prophets, saints, righteous servants of God, pure Monotheists, and gnostics were.
-Profundities of Prayer, Ayatullah Sayyed ' Ali Khamenei, pp-45, 46 [Tr].