Dhikr of Allah is the most praiseworthy work to earn Allah's pleasure, the most effective weapon to overcome the enemy, and the most deserving of deeds in reward.
"And be not you as those who forgot Allah and therefore He caused them to forget their own souls. Such are the losers." [Surah Hashr; verse 19]
"Then woe unto those whose hearts are hardened against the remembrance of Allah. Such are in plain error." [Surah Zumar; verse 22]
"O ye who believe! Remember Allah with much remembrance; and glorify Him morning and evening." [Surah al-Ahzab; 41-42]
"I am near to the thought of My servant as he thinks about Me, and I am with him as he remembers Me. And if he remembers Me in his heart, I also remember him in My Heart, and if he remembers Me in assembly I remember him in assembly, better than his (remembrance), and if he draws near Me by the span of a palm, I draw near him by the cubit, and if he draws near Me by the cubit I draw near him by the space (covered by) two hands. And if he walks towards Me, I rush towards him." [Hadith Qudsi]
Abu Mas'ud reported that the Prophet (pbuh) said, "If anyone recites the last two verses of
Abu Malik al-Ash'ari (RA) reported: the Messenger of Allah (pbuh) said, "Wudu' is half of Salat, and the expression: Subhan'Allah (Glory be to Allah)' fills the Balance, and the expression: Alhamdulillah (praise be to Allah)' fills the space between the heavens and the earth." [Muslim]
The Messenger (Muhammad SAW) believes in what has been sent down to him from his Lord and (so do) the believers. Each one believes in Allah, His Angels, His Books, and His Messengers. They say, "We make no distinction between one another of His Messengers" - and they say, "We hear, and we obey. (We seek) Your Forgiveness, our Lord, and to You is the return (of all)."
Allah burdens not a person beyond his scope. He gets reward for that (good) which he has earned, and he is punished for that (evil) which he has earned. "Our Lord! Punish us not if we forget or fall into error, our Lord! Lay not on us a burden like that which You did lay on those before us (Jews and Christians); our Lord! Put not on us a burden greater than we have strength to bear. Pardon us and grant us Forgiveness. Have mercy on us. You are our Maula (Patron, Supporter and Protector, etc.) and give us victory over the disbelieving people.
Abu Sa'id reported that the Prophet (pbuh) asked, "Can anyone of you recite a third of the Qur'an during the night?" The Companions considered this rather difficult and they said, "Who among us can do so, O Prophet of Allah?" Thereupon the Prophet (pbuh) said, "(Say :) He is Allah, the One and Only; Allah, the Eternal, Absolute; He begets not, nor is he begotten; and there is none like unto Him.'' (The reference here is to recitation of Surah 112 (Surah Ikhlas) of the Qur'an, which the Prophet (pbuh) described as equivalent to reciting one-third of the Qur'an. [Bukhari, Muslim].
"Abu Hurairah (RA) reported: the Messenger of Allah (pbuh) said, "He who recites after every prayer: Subhan'Allah (Glory be to Allah) thirty-three times; Alhamdu lillah (praise be to Allah) thirty-three times; Allahu Akbar (Allah is Greatest) thirty-three times; and completes the hundred with: La ilaha illallahu, wahdahu la sharika lahu, lahul-mulku wa lahul-hamdu, wa Huwa `ala kulli shai'in Qadir (there is no true god except Allah. He is One and He has no partner with Him. His is the sovereignty and His is the praise, and He is Omnipotent), will have all his sins pardoned even if they may be as large as the foam on the surface of the sea." [Muslim]
Abu Hurairah (RA) reported that the Prophet (pbuh) said, "Whoever says, 'La llaha illa-Allahu wahdahu la sharika lahu, lahul-mulku wa lahul-hamd wa huwa 'ala kulli shai'in qadir' a hundred times during a day will have a reward equivalent to the reward for freeing ten slaves. Besides, a hundred good deeds will be recorded for him and a hundred bad deeds of his will be wiped off, and it will be a safeguard for him from Satan that day until evening, and no one will be better in deeds than such a person except he who does more than that.'' [Bukhari, Muslim, Tirmidhi].
"Sa'ad bin abi Waqqas (RA) reported: the Messenger of Allah (pbuh) used to seek (Allah's) protection after prayers in these words: "Allahumma inni a`udhu bika minal-jubni wal-bukhl, wa a'udhu bika min an uradda ila ardhalil-`umur, wa a`udhu bika min fitnatid-dunya, wa a`udhu bika min fitnatil-qabr (O Allah, I seek refuge with You from cowardice, miserliness and from being sent back to a feeble age; and, seek refuge with You from the trials of this life and those of the grave)." [Bukhari]