Alien Seed (1989)

aka: But Deliver Us From Evil

A young student (Shellie Block) is kidnapped and impregnated by aliens who wish her to conceive a messiah to save Earth from man’s corruption. But when the woman turns up murdered, her sister (Heidi Payne), who has vowed revenge, finds herself to be the new target for the alien conception, for the alien prophecy can not be ignored. Also stars Erik Estrada.