Praise be to Allah.
One of the things that are well-known and well-established in Islamic teachings is that the word of Tahweed (Laa ilaaha ill-Allah – there is no god but Allah) will benefit the one who believes in it in the hereafter, for he will be one of the people of Paradise and will be saved from the Fire, if he understands what it means and acts in accordance with it.
Shaykh Sulaymaan ibn ‘Abdillah ibn Muhammad ibn ‘Abd al-Wahhaab (may Allah have mercy on him) said:
It was narrated that ‘Ubaadah ibn as-Saamit said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “Whoever bears witness that there is no god but Allah alone, with no partner or associate, and that Muhammad is His slave and His Messenger, and that ‘Eesa (Jesus) is His slave and His Messenger, and His Word that He bestowed upon Maryam and a soul created by Him, and that Paradise is true, and that Hell is true, Allah will admit him to Paradise, whatever his deeds may be.”
The words “Whoever testifies that there is no god but Allah” mean: Whoever utters these words, understanding their meaning and acting in accordance with them both inwardly and outwardly, as indicated in the verses (interpretation of the meaning):
“So know, [O Muhammad], that there is no deity except Allah” [Muhammad 47:19]
“but only those who testify to the truth [can benefit], and they know” [az-Zukhruf 43:86].
As for uttering these words without knowing what they mean or acting in accordance with them, that is not beneficial, according to scholarly consensus. End quote from Tayseer al-‘Azeez al-Hameed (p. 51).
But this knowledge of the meaning of these words and what they require is something that every Muslim must learn in general terms, and that will suffice him. There is no report from the Prophet (blessings and peace of Allah be upon him) to indicate that he explained to every new Muslim these conditions in such detail as is found in scholarly books.
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
Undoubtedly everyone must believe in what the Messenger brought in general terms, and undoubtedly knowing what the Messenger brought in detail is a communal obligation, because that comes under the heading of conveying that with which Allah sent His Messenger, and it comes under the heading of reflecting upon the Qur’an and understanding it, teaching the Book and wisdom, preserving the Qur’an and Sunnah, calling people to goodness, enjoining what is right and forbidding what is wrong, calling people to the path of the Lord with wisdom and beautiful preaching, debating in the way that is best, and other things that Allah has enjoined upon the believers. This is a communal obligation upon them. End quote from Dar’ Ta‘aarud al-‘Aql wa’n-Naql (1/51).
It is not obligatory upon every Muslim to learn all these conditions, and not knowing them does not undermine his faith; rather what is required of him is to act in accordance with these conditions and to have sound faith.
This is what the Muslim should do – even if he is an ordinary Muslim, so long as his heart is filled with love for Allah and His Messenger and love of obeying them, and he has respect for the religious texts and acts in accordance with whatever he learns of them, to the best of his ability.
Shaykh Haafiz al-Hakami (may Allah have mercy on him) said:
The one who says Laa ilaaha ill-Allah will not benefit from merely uttering these words, unless he learns and complies fully with these seven conditions. What is meant by complying fully with them is when a person understands them all and adheres to them all, without thinking or doing anything that is contrary to any of them.
What is meant by learning them is not merely listing the phrases and memorizing them. How many ordinary (relatively uneducated) Muslims understand them and comply fully with all of them, and adhere to them, even though if they were told to list them, they would not be able to do so.
And how many there are who have memorized them and are able to list them readily, but you see them doing things that are contrary to them. Guidance is in the hand of Allah, and it is Allah Whose help we seek. End quote from Ma‘aarij al-Qubool (2/418).
Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allah have mercy on him) said:
What is required of all Muslims is to fulfil this word of Tawheed by paying attention to these conditions. Once the Muslim understands the meaning of this word and adheres to it, he is a Muslim whose life and wealth are sacred, even if he does not know these conditions in detail, because what matters is to learn the truth and act upon it, even if the believer does not know the details of the conditions required. End quote from Majmoo‘ Fataawa ash-Shaykh Ibn Baaz (7/58).
But knowing these conditions is a communal obligation, so there must be some among the ummah who know about these conditions and teach them to people. This comes under the heading of conveying that with which Allah sent His Messenger (blessings and peace of Allah be upon him), as mentioned in the quotation above from Shaykh al-Islam Ibn Taymiyah.
Shaykh al-Islam also said:
With regard to what individuals are required to know, this varies according to their abilities, needs and knowledge, and what is required of them as individuals. It is not required of one who is not able to comprehend knowledge to learn some branches of knowledge or to understand some subtle issues therein, in contrast to the one who is able to do that. One who studies the religious texts and understands them is required to examine them in detail, whilst that is not required of one who has not studied these texts. More is required of the mufti (scholar who is qualified to issue fatwas), muhaddith (scholar of hadith) and one who engages in scholarly debates than is required of one who is not engaged in such pursuits. End quote from Dar’ Ta‘aarud al-‘Aql wa’n-Naql (1/52).
And Allah knows best.