Most people turn to their boss, owner, then the government, and finally God.
Allah is telling us that the height of intellectual progression is to turn to Him fully. So He is the true Master (Rabb), He is the true King (Malik), and He is the true God (Illaah) that you should turn to.
Prophet Ibraheem who fully internalized this - he was a man who turns to Allah for everything. He truly knew that Allah is the One who can only fix your problems.