1) If Dog forgets himself, so does the voice that raged within him. After their passing, a new voice speaks within the mutant's shell. It is difficult for the voice to remember the two it once was... there was the beast, Dog consumed by hunger... and the other in reverse... the one consumed by control. Both were driven by need for the other. The Courier brought them together, somehow, joined the two into one. All that happened at the Sierra Madre, is a faint memory to the new personality... like a flickering light in the clouds of the mind. The new voice does not think of the Courier again until the battle at the Divide reaches his ears. The battle between the two couriers, beneath the torn skies and the Old World flag... each bearing a message for the other. And the mutant prays that the Courier that had saved him... had been saved in return.

2) If freed of both Dog and the one who held Dog's leash, the other voice resumes control. First the mind, then finally, the mutant's shell. His first act is to tend the scars on the body with careful hands, slowly healing all the scars except the ragged name torn on his chest. He briefly thinks of remaining at the Sierra Madre. But it is a monument built by humans, representing something he no longer needs. He begins walking west, in search of others like him. As he does, he speaks of the courier who had set him free and allowed his life to begin again.

Seems like in both of these ending, Dog/God lost both personality, but what is the different between 1 and 2? How can get either the 1st or 2nd ending?

What is the ending if I let God get the full control?

Ending #2 above is the one with God in full control.

Ending #1 requires you to pass a very high (85) Speech check. Ending #2 requires passing a slightly lower (75) Speech check, plus you cannot have used the tape to put God away when you first met him at the police station.