Shaikh Ṣāliḥ Al-Fawzān, may Allāh protect him, said:

Mankind has been created to worship Allāh, [being a slave only to Him]; if he then abandons that, he becomes a slave to the devil. So he’s [always] a slave, [no matter what]—there’s no escaping that.

Iʿānah Al-Mustafīd, p. 169, as quoted by Shk. Fawāz Al-Madkhalī. 15 Jan 23.