via Got Questions (December 26, 2018)— “How is Satan god of this world (2 Corinthians 4:4)“:

“The phrase ‘god of this world’ (or ‘god of this age’) indicates that Satan is the major influence on the ideals, opinions, goals, hopes and views of the majority of people. His influence also encompasses the world’s philosophies, education, and commerce ….

This is not to say that he rules the world completely; God is still sovereign …. When the Bible says Satan has power over the world, we must remember that God has given him domain over unbelievers only ….

You may ask why mankind does not simply receive the free gift of salvation (John 1:12). The answer is that Satan — the god of this world — has tempted mankind to follow his pride instead ….

In addition to providing a complete answer to this question available free online, Got Questions Ministries offers this content a 3:07-minute YouTube video.