Verily the best Dhikr is La Ilaha illallah (There is no God but Allah)

May Allah سبحانه و تعالى‎  shower His blessings on the Prophet Muhammad صلى الله عليه وسلم. 

May Allah سبحانه و تعالى  be pleased with all the Prophets, Sahabahs, Tabi'un. May Allah  سبحانه و تعالى‎ have mercy on the souls of all the righteous individuals of the ummah.

Ameen

Verily lailaha ilallah is the supreme utterance of magnifying the glory of Allah سبحانه و تعالى‎. It is clearly stated in many hadith regarding the value that these words contain. The gold that is enriched in this sublime statement is boyond reckoning.

The Prophet -- Allah bless and greet him -- said: "The best remembrance of Allah is to say: There is no god but Allah."  

The Prophet -- Allah bless and greet him -- said: "Saying subhan allah (glory to Allah) is half the balance and saying al-hamdu lillah (all praise belongs to Allah) fills it, and there is no veil between La ilaha illallah and Allah Himself (i.e. it is not even weighed in the Balance), it reaches Him directly."

The best of my sayings and of the sayings of all Prophets before me is: There is no god but Allah alone, without partner, to Him belong all sovereignty and glory, and He has power over all things." Narrated by Tirmidhi.

Belief is seventy and some branches. Its lowest branch is the removal of harm from the road while its highest is to say: There is no god but Allah."

The Prophet -- Allah bless and greet him -- said that Allah will save a man of his community the record of whose sins fills 99 books, each book extending as far as the eye can see. Against all this will be weighed the one good deed that he has, which is his witnessing that there is no god but Allah and that Muhammad is His Messenger, and it will outweigh all the rest. The Prophet -- Allah bless and greet him -- then said: "Nothing is of any weight with Allah's Name."

From the above hadiths it is clear how powerful it is to repeat the greatest words that one could ever utter. There are many other types of dhikr that an individual could indulge in however the dhikr of La ilaha illallah outweighs them all.  

If one was to put all the powers and strength of this world on a scale, just a piece of paper with la ilaha ilallah written on it would outweigh the latter.

PARADISE FOR UTTERING LA ILAHA ILLALLAH 

      "The Prophet -- Allah bless and greet him -- said: "Whoever says: there is no god but Allah enters Paradise."

"Whoever WITNESSES that there is no god but Allah alone enters Paradise."

"Everything has its key, and the key to Paradise is the witnessing that there is no god but Allah."

"Whoever breathes his last with the words: La ilaha illallah, enters Paradise."

Whoever dies knowing full well that there is no god but Allah, enters Paradise."

The power of these words contain rewards when uttered by a believer. One should really hold tight to lailaha ilallah. This is the key to opening the gates of paradise, cling onto them with conviction and honesty.

However this does not mean that if you just utter these words you are guaranteed paradise. In hadiths its clearly emphasised whoever witnesses, believes with full devotion, not associating any partners with Allah. Trusts Allah and worships him with submission will gain paradise.

Lailaha illallah is not an easy route or a free ticket to jannah, one has to believe firmly from his heart, 
This ticket to paradise has to come with sincerity and devotion.

FIRE IS UNLAWFUL/ PROHIBITED

If anyone comes on the Day of Resurrection who has said La ilaha illallah sincerely with the intention to win Allah's pleasure, Allah will make Hellfire forbidden for him."

Uthman ibn `Affan said: I heard Allah's Messenger say: "Verily, I know a phrase which no servant utters truthfully from his heart except the Fire is made unlawful for him." `Umar ibn al-Khattab said: "I shall tell you what that phrase is. It is the kalima of sincerity with which Allah has empowered Muhammad and his Companions, the kalima of fear of Allah which Allah's Prophet enjoined upon his uncle Abu Talib on his deathbed: the witnessing that there is no god but Allah."

No servant is true to his word on the Day of Resurrection, saying: No god but Allah in order to seek Allah's good pleasure, except Allah will make the Fire unlawful for him."

One should make it a constant habit of uttering the this dhikr and implementing it into their lives. It will be a source of light for the akhirah and righteous guidance for this world. One should repeat the words with devotion and love. Firmly trust in Allah alone, associating no partners or any other false deities. Firm rigid conviction and belief is the key. If you want a shield against the fire then instil the best of phrases into your heart.

The best deed is belief in Allah alone, then struggle in the way of Allah, then pilgrimage that is accepted: these outweigh all deeds the distance of East to West."

Mu`adh ibn Jabal said that the last he spoke with the Prophet -- Allah bless and greet him -- he asked him: "What action is most beloved to Allah?" And the Prophet -- Allah bless and greet him -- replied: "That you die with your tongue still moist with the mention (dhikr) of Allah."

May Allah سبحانه و تعالى‎ make La ilala illallah the prime focus of our lives, remove obstacles that are trying to eliminate the utterance of this elevated dhikr and help us to stay on the path of guidance.

May Allah سبحانه و تعالى‎  keep us steadfast on the deen and create a bond of unity and success.

We ask Allah سبحانه و تعالى‎  to protect us from the fitna of Dajaal the fitna of Jinn and the fitna of this world. Protect us from the trials and tribulations of this world and the evil that exists. Save us from the whispers of Iblis the accursed during life and death. Save us from the punishment of the grave and on the day of Qiyamah. 

May Allah سبحانه و تعالى‎ give us entry into Jannah with his mercy. 

Ameen.