Q: What are the conditions of saying: "La ilaha illaAllah (there is no deity but Allah)", and is it sufficient to say it without understanding its meaning and its consequences?
A: It is necessary to understand and realize the word ("La ilaha illaAllah"). "La ilaha illaAllah" is the best of words and the basis of the Din (religion of Islam). With it the prophets (peace be upon them) started their mission of guiding their people and the first thing that the Messenger (peace be upon him) called his people to say was: "La ilaha illaAllah" so that they may succeed and prosper.
And We did not send any Messenger before you (O Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ) but We revealed to him (saying): Lâ ilâha illa Ana [none has the right to be worshipped but I (Allâh)], so worship Me (Alone and none else).
Every Messenger said to his people: Worship Allâh! You have no other Ilâh (God) but Him.
It is the essence of the Din; therefore, the one saying it must understand its meaning, as it means that there is no true god to be worshipped except Allah. It has certain conditions, and they are: knowledge of its meaning, certainty and lack of doubt over its truth, sincerity to Allah Alone in this regard, faithfulness in the heart and on the tongue, love for what it indicates of sincerity to Allah and acceptance of this and submission to Him, Tawhid (belief in the Oneness of Allah/ monotheism), renunciation of Shirk (associating others with Allah in His Divinity or worship) and disavowal of the worship of any other than Allah, and belief in the falsity of such worship.
All these are among the conditions of saying: "La ilaha illaAllah", and the validity of its meaning. The believing man and woman say it, renouncing with it the worship of any other than Allah, and declaring submission to AlHaqq (the Truth), acceptance of it, love for Allah, belief in His Oneness and sincerity to Him, while harboring no doubt of its meaning. For some people say it without believing in it, such as the hypocrites, who say it although doubting or denying it.
It is necessary to have knowledge, certitude, truthfulness, sincerity, love, submission, acceptance, and repudiation. These conditions are included in the following lines of verse:
Knowledge, certainty, sincerity, love, submission, and and trustfulness with acceptance of it And an eighth is your denial of other than Allah being deified anything
May the peace and blessings of Allah be upon our Prophet Muhammad, and his family and Companions.