How did Satan fall from heaven?

The honest answer is that the Bible never tells this story directly in one place—Christians have pieced it together mostly from Jesus' brief comment in Luke 10:18 ("I watched Satan fall from heaven like lightning") and from two Old Testament poems, Isaiah 14 and Ezekiel 28.

Here's the important, often-overlooked detail: those Old Testament passages are written, on their surface, as taunts against two human kings—the king of Babylon in Isaiah, the king of Tyre in Ezekiel. Most scholars agree their immediate meaning is about those rulers' arrogance and downfall.

Very early on, Christian and Jewish readers noticed the language in these poems seemed to overflow human description—talk of heaven, God's mountain, and being "cut down" felt bigger than any earthly king. So they read these texts as describing Satan's fall too, layered underneath the description of the king.

That's a long-standing, reasonable Christian reading—but it's worth being honest that it's an interpretation built on hints, not a single clear narrative Scripture spells out start to finish.