Where by "Christianity" you mean the Epic of Gilgamesh?
Anyway, simulating a human has the main bonus that we don't have to fully understand how intelligence works to make progress.
The desire for personal immortality is the oldest known human desire, it's written down in the oldest story we know http://en.wikipedia.org/wiki/Gilgamesh, or still standing in the pyramids and similar burial places all over the world.
Where by "Christianity" you mean the Epic of Gilgamesh?
Anyway, simulating a human has the main bonus that we don't have to fully understand how intelligence works to make progress.