Nebuchadnezzar ruled the world from Babylon. The Greeks became predominant under Alexander the Great. The Roman Empire held sway in the First Century. Cults grew around emperor worship. Citizens gladly made the confession, "Caesar is Lord."
All of this was contrary to the ancient Jewish faith and to Christianity. Three Jewish boys, Shadrach, Meshach, and Abed-nego, refused to bow down to the golden image erected by Nebuchadnezzar. The king had them thrown into a fiery furnace (Daniel 3:8-26).
Christians faced a similar fate if they refused to worship Caesar. To confess the emperor as Lord was contrary to their faith. Romans 10:9 makes this abundantly clear. "If you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you will be saved." To place someone above Christ as an object of worship was blaspheme.
Psalm 24:8 asks a question and immediately gives the answer. "Who is the King of glory? The Lord strong and mighty, the Lord mighty in battle." Once again, this Lord is Jesus Christ (Romans 10:9). And the Bible maintains, "Whoever will call on the name of the Lord will be saved" (Romans 10:13, Joel 2:32).
The words of Christ are therefore far better than the sayings of earthly kings that pass away. "The word of the Lord endures forever" (1 Peter 1:25).