Is there another motivation for christian belief?

[SenpaiNoticeMeYouBlindShmuck]

Power.

"I'm chosen by God"

"I'm a better person than you"

"You're a douche, I'm going to enjoy watching you suffer in the next world"

"The poor will inherit the earth"

Christianity is rather unique in the way it turns weakness or deficiencies into virtues. The downtrodden, the resentful, the sickly and the weak; they're going to have the last laugh at the very end at everyone who stood over them in life. Zoroaster may well have had a similar idea, but there's not so much evidence to suggest he was as focused upon laying out the specifics on how to behave (he had plenty to say about ritual); hence why the Zoroastrian's as far as I know haven't got a reason to hate women who've had abortions or gays.

Perhaps I'm taking too overtly a Nietzschean/Freudian view upon this. I think a longing for power lies at the core alongside fear.

Power is a motive once you're in, when you can then use fear as a tool.

I agree, although I do think the promise of power is tempting too.

Look towards how the role of cleric in any abrahamic faith is presented. A semi mystical scholar, in some tradititions even blessed with magical powers to turn food into flesh and control the destinies of your flock. There's an aura of mystique and community some traditions have managed to build up, and that is something that attracts new converts.

It doesn't need to be a mystique in the incense and chastity sense, when the Osmond's began selling records more people across the Western world began attending Mormon meeting houses and converting. Granted it wasn't a huge number, but it was significant enough to be correlated to the beginning and peak of their careers (particularly Donny's for female converts). They portrayed an image of being blessed with wealth and an idyllic family life, and outsiders pounced on it eager to aquire the same happiness for themselves. To this date this remains the core of Mormon missionary activity, milk before the meat, show them how better off we are with God in our corner and what they can get if they join us.

I don't imagine it was very different for the Early Christians, although they were likely far more prone to the promise of supernatural power. If people were willing to die to acquire passage into the Kingdom of Heaven, it must have been something valuable. Like how everything is worth what you're willing to pay for it, if you see other people pay a lot for it odds are you'll imagine it to be worth a lot too. Goes for everything from a Damien Hirst piece to martyrdom.

If I throw a few streaks of paint at a canvas I likely have devalued a canvas. However if I say Pollock did it it suddenly becomes valuable. It gains worth and becomes a symbol of power, therefore elevating both its worth and my own in the view of others. Of course, only provided the viewer believes it is what it is claimed to be!