Every once and a while heretics turn out to be a whole lot of fun! I suppose it takes one to know one. How I came to study the thirteenth century Cathars this weekend is uninteresting, but what I found was the most bizarre Christology that I've ever encountered.
Disclaimer: we only know about Catharism through contemporary Catholic polemic. Keep in mind that they were accused of bestiality, incest and *gasp* contraception, among other nasty things. In other words, their theological opponents accused them of being anti-Catholic at every turn when it came to sexuality (and a host of other issues). On the contrary, the Cathars probably practiced sexual abstinence to a great extent. So take this all with a grain of salt.
It seems that (in keeping with their radical dualism) the Cathars believed in two Gods (one good; one evil) and two Christs (one celestial; one terrestrial). Both of the Gods had wives. The good God had two wives (sounds like the beginning of a word problem). The son of the evil God was Lucifer. Lucifer seduced one of the wives of the good God and she gave birth to Jesus. So one of these Christs was the son of Lucifer.
cf. this fine book.
Here is the question. It is unclear to me which Jesus she gave birth to.
Was it the terrestrial Jesus or the celestial Jesus?