The right word on the realization of tawhid, followed by questions & answers, by Ch. Abd Al-'Aziz Ar-Radjhi, Bilingual (FR-AR)

Title in Arabic: القول السديد في بيان التوحيد (Al Qawl As-Sadid fi Bayan At-Tawhid)

The Prophet (sws) is sent to preach Tawheed and the religion of all the Prophets (alayhim salam) and they are all sent to preach Tawheed.

Tawhid is to sincerely dedicate one's works to Allah, so that they are not imbued with association, and to draw near to Allah by all the pious works one does.

Worship is an exclusive right of Allah towards His servants, and it is for this that He created beings.

All actions that the Sharia commands or recommends must be devoted exclusively to Allah, among others, prayer, fasting, zakat, hajj, filial piety, keeping ties of kinship, invocation, vow, imploring assistance from Allah, fear, ritual sacrifice (slaughter), love, fear, hope and others... All must be dedicated to Allah. This is Tawheed.

Indeed, all action is vain, unless it is dedicated to Allah and for the reward of the Hereafter. In addition, it must be Sharia compliant.

If the person fails in this principle, he will necessarily fall into Shirk, and if Shirk is associated with worship, it makes it vain. As if a person does his ablution, but following the exit by one of the two ways his purification becomes invalid. It is also the case of a monotheistic person who commits Shirk, his monotheism becomes null, and if monotheism becomes null, all works will be too.