He who sins is of the devil, for the devil has been sinning from the beginning. To this end the Son of God was revealed, that he might destroy the works of the devil.
Certainly, it is wrong to think of Satan's sharing, in any manner, the control of the universe with God. That he was the leader of a band of rebellious angels would appear to be a proper deduction from Jesus' mention of "Satan and his angels"  (Matthew 25:41), leading to the supposition that Satan himself was, at first, an angel of God who led some of his fellow-angels into rebellion.  This is an awesome subject, and little more than a few suggestions may confidently be offered.  That there is indeed a being of great magnitude of powers, an inveterate enemy of mankind, the prince of this world, the ruler of the world's darkness, a prince of evil, who has organized and directed the wickedness of mankind is a fact so plainly set forth in the New Testament that only an unbeliever may deny it. The Lord's Prayer is a constant testimonial to the existence of Satan: "Deliver us from the evil one!"