This question has intrigued and confused many Bible scholars, pastors and theologians. Satan's claim that he could give Yeshua all the kingdoms of the world, is seen by some as biblical proof that Satan is king - that he is in charge of all the kingdoms of the whole world.
But what did Yeshua himself say about Satan and his claims? He said that Satan is a liar, and the father of lies. The Hebrew Old Testament further states very clearly and repeatedly that YHWH is king of the whole world, not Satan.
The puzzling problem, however, is that the Greek Revelation contains several verses which clearly contradict the Tanach, and seem to confirm the idea that YHWH is not king right now, and that He will only begin to reign in future. E.g., Rev. 11:15 (ESV): "...The kingdom of the world has become the kingdom of our Lord and of his Christ, and he shall reign forever and ever."
If YHWH will only become the king when He overcomes Satan one day in future, it clearly implies that in the meantime, Satan is king.
So, who is king right now, YHWH or Satan? Watch video 4 on the Hebrew Revelation to find the answer to this question!