What is the meaning of sincerity in worship?

Question:
May Allah reward you with good and do you good. A listener from Makkah al-Mukarramah, who indicated his name with the letters S and D, says: I want you, Honorable Shaykh, to speak to us about sincerity and how to avoid its opposite. What is showing off (riya')? And what are the causes that keep us away from shirk (associating partners with Allah)? We ask for your answer. May Allah preserve you.

Answer:
Sincerity is obligatory for the Muslim to be sincere to Allah in his worship. The meaning of sincerity is purifying the intention for Allah in worship and in the niyyah (intention), and that the person does not have a worldly aim or hope in his worship. If he seeks worldly gain with his deeds, or seeks praise from people, or seeks for people to see him, or the like of that, then this nullifies the deed, corrupts the deed, and brings about the anger of Allah (Glorified and Exalted is He). Allah (Glorified and Exalted is He) says: , and He says (Glorified and Exalted is He): We call upon . My religion is sincerity. Sincerity is singling out Allah (Exalted and Majestic is He) with the intention and the aim, and that there be no partnership for other than Allah (Glorified and Exalted is He) in the person's intention. In the Qudsi Hadith, Allah (Glorified and Exalted is He) says: . This is sincerity. And you only reach it when you know the types of shirk, the hidden and the apparent, in order to avoid them. And this is only achieved by studying these matters and knowing them with insight, and asking the people of knowledge; because the one who does not know evil is likely to fall into it. So it is obligatory for the Muslim to learn tawhid (the oneness of Allah) and to know the types of shirk and the ways of entering into shirk, in order to avoid them and beware of them. So a person cannot be sincere and avoid shirk unless he knows it, knows its types, and knows its ways of entry, so that he can avoid them. Yes.