@anhphan
It was the sin of pride and disobidence to God . Isaiah ch14 and Ezekiel ch 28 is about satan
Isaiah 14:12 “How you are fallen from heaven, O Day Star(satan), son of Dawn!How you are cut down to the ground, you who laid the nations low!13 You said in your heart, ‘I will ascend to heaven;
above the stars of God I will set my throne on high;I will sit on the mount of assembly in the far north;14 I will ascend above the heights of the clouds, I will make myself like the Most High.’
15 But you are brought down to Sheol, to the depths of the Pit.
Ezekiel 28:1The word of the Lord came to me: 2 “Son of man, say to the prince of Tyre, Thus says the Lord God:“Because your heart is proud, and you have said, ‘I am a god,
I sit in the seat of the gods, in the heart of the seas,’yet you are but a man, and no god, though you consider yourself as wise as a god—3 you are indeed wiser than Daniel; no secret is hidden from you;4 by your wisdom and your understanding you have gotten wealth for yourself,and have gathered gold and silver into your treasuries;