With this last episode i noticed that it seemed more like Jacob and MIB may be equal rather than Jacob being more powerful. This reminded me of a religion that i briefly learned about last year, so i read up on it.
An ancient religion called Zoroastrianism may explain this. In it there is the belief in a god called Ahura Mazda who is all good and the creator of everything. His nemesis is Angra Mainyu who is pure evil. They are in a constant battle over trying to prove whether humanity is intrinsically good or evil. Ahura Mazda also believes in the importance of free will just like Jacob. He constantly works to keep evil at bay also like Jacob does. Ahura Mazda does not work alone however. He has divine attributes called Amesha Spentas. There are SIX of them (possibly a hint at the oceanic six?). They are
* Vohu Manah - Good mind and good purpose.
* Asha Vahishta - Truth and righteousness.
* Spenta Ameraiti - Holy devotion, serenity and loving
kindness
* Khashathra Vairya - Power and just rule.
* Hauravatat - Wholeness and health. (possibly Jack since
he's a doctor)
* Ameretat - Long life and immortality. (wouldn't fit with
oceanic six part but possibly Richard)
Ahura Mazda and Angra Mainyu are in a constant battle between each other, but eventually at the end of time a savior will come and the dead will be revived (possibly Hurley since he can already see the dead)
Zoroastrianism has influenced much of the Judeo-Christian belief system along with other religions. Many of these beliefs somehow come up on Lost.
This is merely an observation, but it is a possibility. If you have an idea on what the other Amesha Spentas might be or anything else please post it.