There is a false teaching going around that Cain was the son of the serpent. It is called the Serpent seed doctrine, dual seed or two-seedline doctrine. It is a controversial doctrine according to which the serpent in the Garden of Eden mated with Eve, and the offspring of their union was Cain.
This belief is held by some adherents of churches with a racialized theology (Christian Identity Movement) which promote a “Eurocentric” interpretation of Christianity, and claim that the Jews, as descendants of Cain, are also descended from the serpent. Several adherents such as William M. Branham (1909–1965) and Arnold Murray teach serpent seed theology in a non-racial context, but the best known are those teachers which are considered to be white supremacists’. In one variation of Christian thought called British Israelism teaches that many white Europeans are the literal descendants of the Israelites through the ten tribes which were taken away into captivity by the armies of Assyria. It asserts in addition that White European Israelites are still God’s Chosen People, and that modern Jews are not at all Israelites nor Hebrews, but are instead descended from people with Turco-Mongolian blood, or Khazars, or are descendants of the Biblical Esau-Edom, who traded his birthright.
There are differences between what group believe, but the basic belief is that the Original Sin was an act of sexual intercourse between Adam and Eve. Prior to that act, the serpent sexually seduced Eve; further, that Cain was conceived by that act.
The doctrine that Eve mated with the serpent, or with Satan, to produce Cain was explicitly rejected as heresy by the early church father Irenaeus around 180 AD. A similar doctrine appeared in Jewish midrashic texts in the 9th century and in the Targum of Pseudo Jonathan. It is considered a false doctrine by mainstream Protestant and Catholic theologians.
- Fallen Angels in the Garden of Eden (fallenangels-ckquarterman.com)
- Serpent was not a Snake (fallenangels-ckquarterman.com)
- Watchers (fallenangels-ckquarterman.com)