Sincerity in Action and Its Effect on the Acceptance of Worship

Question:
We begin with a question from our brother Taha from Riyadh. He says: Shaykh Salih, may Allah keep you safe, tell us about the effect of sincerity in actions and worship, and what are the means that help one to be sincere in worship? And is a person rewarded for his righteous deed even if it was not pure?

Answer:
In the name of Allah, the Most Gracious, the Most Merciful. Praise be to Allah, Lord of the worlds. And may Allah send prayers and blessings upon our Prophet Muhammad, and upon his family and all his Companions.
As for what follows, sincerity in righteous deeds is the foundation for their acceptance, for a righteous deed is not accepted unless it is pure for the sake of Allah. It must contain no shirk (associating partners with Allah), neither major nor minor. This is the meaning of sincerity: that the deed is pure from shirk, for Allah (Mighty and Majestic). This is through the intention of its doer and the purpose of its doer. And intentions and purposes are known only to Allah. And Allah (Exalted and Majestic is He) knows the sincere one from the one who is not sincere. Even if a person adorns himself and claims sincerity while he is not so, Allah knows what is in his heart. From this, it is obligatory for the Muslim to care about sincerity.
And that is by learning the method of doing deeds in accordance with the Book and the Sunnah, so he does not act out of ignorance, and he does not act by following (taqlid) so-and-so or so-and-so, but rather he acts in accordance with the Book and the Sunnah. And he must also, in order for sincerity to be realized for him, beware of shirk entering into his deeds. He must beware of major shirk and minor shirk. One may be safe from major shirk, but he is not safe from minor shirk. There is danger in minor shirk.
As he (peace and blessings be upon him) said to his Companions , . He was asked about it, and it was said that riya' means that a person shows off with his deed, seeking praise and commendation, and he adorns his deed in order to be praised. So he has no reward for it, because he did not make it pure for Allah (Mighty and Majestic).
And among what encourages sincerity and establishes it in the heart is for a person to always and forever remember that Allah does not accept from him except what is pure for Allah (Mighty and Majestic) and correct in accordance with the Sunnah of the Messenger of Allah (peace and blessings be upon him). Allah the Exalted said: Fudayl ibn 'Iyad (may Allah have mercy on him) was asked, "What does 'do the best of deeds' mean?" He said, "Make it pure and make it correct." He was asked, "O Abu 'Ali, what does 'make it pure' mean, and what does 'make it correct' mean?" He said, "Make it pure means that it is pure for Allah, and make it correct means that it is correct in accordance with the Sunnah of the Messenger of Allah. If the deed is pure but not correct, it is not accepted, and if it is correct but not pure, it is not accepted, until it is both pure and correct."
So from this, it is directed and obligatory for every Muslim to care about the deed by which he draws near to Allah, by purifying it from the impurities of shirk, bid'ah (religious innovation), and newly invented matters, so that Allah (Glorified and Exalted is He) may accept it. For if the deed is not pure, it is not accepted, and if it is not correct, it is not accepted. His (peace and blessings be upon him) saying , and in a narration , means it is returned to him and not accepted. And Allah (Exalted and Majestic is He) only accepts from deeds what is pure for His face.
And Allah (Exalted and Majestic is He) says in the Holy Hadith . And in a narration , He is free from it.

The presenter:
May Allah reward you, Honorable Shaykh, for this blessed introduction regarding sincerity and its effect on worship and transactions.