Now fools who scoff and mock at this answer actually believe (by faith in the unseen) that chaotic primordial matter has either always existed or came into existence together with Time, Natural Law, Natural Selection, Evil, and Life when a Cosmic Egg exploded (Big Bang), thus allowing for an unseen creative energy to act upon matter.
In this faith-system, there really isn't any originating source for life, or consciousness which is why many materialists have been secretly crossing the fluid line between materialism and mystical pantheism to embrace of the latter. Many others, such as C. Arthur Clark, embraced both mystical pantheism and the idea of extraterrestrials in the vain hope that they brought life to earth. But where they supposedly obtained life remains unanswered.