The ancient serpent

Genesis 3 never names the serpent as Satan; the New Testament makes that identification, and Heiser reads the nachash wordplay (serpent, shining one, diviner) as what keeps the Genesis text from being a talking-animal story. Revelation 12:9 gives the figure two functions, slanderer and deceiver, which the Greek titles devil and Satan simply name, and both go back to what the serpent does in Genesis 3. DDD (R. S. Hendel) reads the Eden serpent as a trickster who blurs the lines between animal, human, and divine. He is classed as an animal (Genesis 3:1) yet has human speech, and unlike the humans he deceives he already knows what God confirms afterward, that eating the fruit won't kill them but will open their eyes (Genesis 3:22). DDD also flags that Genesis 3:20 calls the woman "mother of all living" right after the serpent scene, a formula that elsewhere in the ancient Near East is a goddess epithet, possibly a deliberate echo of the serpent's known association with a nude goddess in Canaanite iconography, probably Asherah. Even elsewhere in the New Testament the identification of serpent with Satan isn't automatic: John 3:14-15 uses the bronze serpent of Numbers 21 as a positive picture of Christ lifted up, the opposite value from Revelation's use of the same animal.