We are not qualified to judge the sincerity of the worship of anyone. We may not be fully qualified to judge our own.
Was the king of Babylonian empire a new convert to Yawhism in the stories of deliverance that Daniel recites for us? How much conversion, confession, and conviction is required to qualify as legitimate worship that transforms the heart and mind, reorients the soul, and reconfigured our thinking?
Old King Nebuchadnezzar was pretty impressed with the fireproof prophet and those lion proof boys from Israel He was blown away by their God and His power.
These are reported as his words:
How great are his signs,
how mighty his wonders!
His kingdom is an eternal kingdom;
his dominion endures from generation to generation. (Daniel 4:3, NIV)
Maybe he is just good at blowing smoke in the face of deities or howling with the lions .... or maybe this is true worship . It is hard to tell for sure.
We howl and blow smoke too.
Is that always worship?
I like to think that Nebuchadnezzar became a God-fearing, Yahweh-worshiping convert to truth and that he remained so. I believe that God takes our slightest gesture of "yes" to His invitation and continues the process of drawing us closer and closer to Himself as we take baby steps in His direction.
There is much that led up to the point where he declared God's greatness. He had seen some pretty amazing manifestations of divine power.His words of praise are powerful and seem sincere. It sounds like worship to me.
The answer is in his heart and it is in ours.