Every person must have a focus for his love
Everyone who is too proud and arrogant to worship Allah inevitably worships something else, for man is sensitive and is always motivated by ideas. It is reported in al-Sahih that the Prophet ﷺ said, “The truest of names are Harith and Hammam.” Harith means “one who is active and always doing things”, and Hammam means “one who is always looking for things to do”.
Ideas are the beginning of will, and man always has a will which inevitably needs an objective and a focus. Every person must have an ultimate aim which is the focus of his love and will. If a person does not have Allah as the focus of his love and will, and is too proud and arrogant, he will inevitably have something else as his focus, which will enslave him instead of Allah, and he will be its slave, whether it is wealth, power or images, or something that he takes as a god instead of Allah, such as the sun, moon, stars, idols, graves of Prophets and righteous people, or angels and Prophets whom he takes as lords, or anything else that is worshipped instead of Allah.
If he is a slave to anything other than Allah, he is a mushrik, and everyone who is stubbornly proud and arrogant is a mushrik. Hence Pharaoh was one of the most arrogant of all people and most stubborn in his refusal to worship Allah, and he was a mushrik. Allah says:
“Of old, We sent Musa, with Our Signs and an Authority Manifest, to Pharaoh, Haman and Qarun; but they called (him) ‘a sorcerer telling lies!’… Musa said: ‘I have indeed called upon my Lord and your Lord (for protection) from every arrogant one who believes not in the Day of Account!”…Thus does Allah seal up every heart – of arrogant and obstinate transgressors.” (Ghafir 40:23-24, 27, 35)
“(Remember also) Qarun, Pharaoh and Haman: there came to them Musa with Clear Signs, but they behaved with insolence on the earth; yet they could not overreach (Us).” (al-‘Ankabut 29:39)
“Truly Pharaoh elated himself in the land and broke up its people into sections, depressing a small group among them: their sons he slew, but he kept alive their females…” (al-Qasas 28:4)
“And they [Pharaoh and his people] rejected those Signs in iniquity and arrogance, though their souls were convinced thereof: so see what was the end of those who acted corruptly!” (al-Naml 27:14)
There are many other similar references in the Qur’an.
Indeed, all the evidence indicates that the more arrogant a man is in his refusal to worship Allah, the more guilty he is of associating others with Allah, because the more arrogant he is in his refusal to worship Allah, the more dependent he becomes on the desired goal which is the ultimate focus of his heart and so he begins to worship that which has enslaved him.
The heart can never be independent of other created beings unless Allah is its master and it worships none other than Him, seeks help from none other than Him, places its trust in none other than Him, rejoices only in that which He loves, despises only that which He hates, loves only for the sake of Allah, hates nothing except for the sake of Allah, does not give except for the sake of Allah and does not withhold except for the sake of Allah. The more sincere a person is towards Allah, the more perfect his ‘ubudiyyah becomes and the more independent he becomes from other created beings. The more perfect his servitude towards Allah becomes, the more free he becomes of arrogance and shirk.
Source: Al-Ubudiyah by Shaykh al-Islam ibn Taymiyyah