Ibn al-Qayyim:

Allaah the Most High cut of all means for the Mushrikeen to attach themselves to their false deities, in such an incredible way, only people with understanding will realize how amazing it is.

Because the sole reason why a Mushrik takes a false god besides Allaah and makes it their object of worship is due to their presumption that this being (idol, dead person, trees etc) can bring  them some sort of benefit.

And benefit is only gain through four types of means, these being;

FIRST: The object of worship is an Owner, and by worshipping the object it will grant you what you desire.

SECOND: The object of worship is not an Owner but rather is a partner and can still fulfill your wishes.

THIRD: The object of worship is neither an Owner nor a partner but is a helper to the Owner and can still answer your supplications.

FOURTH: The object of worship is neither an Owner nor a partner, not even a helper but only an intercessor and can thus bring you benefit in such a way.

And Allaah the Most High, refuted each of these four claims throughout the Qur'aan, one after the other, He is the only true Owner (al-Maalik) and has no partners whatsoever, nor does He have any helpers and no one can intercede on anyone's behalf accept by His permission.

[Taken from Madaarij as-Saalikeen 1/343]