Where are you without tawhid

The author of the book, Sheikh al-Najdi, may Allah have mercy on him, said:

“ The essence of it (hanifiya) is that you worship only Allah, sincerely professing this religion .”

Sheikh Salih al-Fawzan (may Allah save him) explains:

“Such is the religion of Ibrahim! Its essence is that you worship only Allah, sincerely professing this religion.
That is, you must combine two things: worship (‘ibada) and sincerity (ikhlas).

If a person worships Allah, but does not do it sincerely, then his worship is worthless.
If a person worships Allah, fasts, performs Hajj and dies, performs prayer, pays zakat, but does not do it sincerely only for the sake of Allah, then his worship is worth nothing.

For example, a person does all this for show and fame. Or a person mixes his worship with polytheism, for example, calling on someone other than Allah, asking someone other than Allah for help in a difficult situation, making a sacrifice not for the sake of Allah, and so on.

Indeed, such a person is not sincere in his worship…..
Sharh on the book Three Questions