They have taken gods besides God to be for them their glory.
Translation endnotes
[19:81] Serving statues is only one of the many ways of committing idolatry or polytheism (7:138). Enjoying mentioning other names besides God's name (39:45), following the religious teachings of clergymen and scholars (9:31; 42:21; 6:148), expecting the intercession of messengers, prophets, and "saints" (2:48; 10:18), and believing that messengers and prophets were infallible (18:110), also fall into the category of idolatry. Despite these clear warnings, since mushriks are in a trance under the hypnosis of Satan, they still wish to deceive themselves as monotheists, since they follow a distorted popular message attributed to a popular monotheist (6:23). See 18:32-42.