If we suggest Jesus 'knew' his final fate as Christians envision it, I'm not sure we can call him 'most' altruistic. The Bodhisattva seem to have a significantly larger scope, since their goodness is towards all sentients, no?
edit to avoid dp
Tim, you have to be very careful if only out of empathy. In discussions of altruism (or environmentalism, or whatever), some people don't play fair. They'll constantly imply that you should put your money where your mouth is, but then if you try to give peeks of your life (showing that you practice what you preach), you'll then get berated as 'smug' or 'holier than thou'. It's a very (!) hard line to walk, somehow giving the impression that you personally try very hard but also think it would be better if people acted like you. A much easier line to walk is the 'haw haw, u so smug!' taunt afterwards.
At some point, a person actually can say "what I do is better than what you do". I mean, it's the natural outcome of what happens when someone tries to apply Kantian ethics. Now, if someone is being smug and rude along different dimensions, that's totally a different thing. But it still suggests that it's prudent to be careful when confronting this smugness, to target it correctly.
I find the concept altruism really interesting, mainly 'cause I think it's an essential way to get the world where I want it to be in time. I found the Ebola outbreak last year quite fascinating, given how many people basically only wanted "the government" to save us (by restricting human rights of other people). The game-winning move was a massive influx of aid in order to snuff the outbreak as fast as possible, followed by a concerted effort to deploy a vaccine. But people didn't seem to want that, they preferred to trickle in aid and employ soldiers to cause quarantine regions and heap scorn on anyone who potentially spread the virus (no matter what they sacrificed to help contain it).
I was boggled, but moreso on right-wing forums. The 'libertarian' mantra is that 'charity should be used to handle tasks requiring government intervention', but I found so many people whose main instinct was to empower bureaucrats with guns to herd healthy people in with sick people. Nearly no one was saying "charity is VASTLY cheaper here!" or "early aid protects human rights" or "the Free Market will not provide a vaccine without a wealthy customer". (I found it weird, too, since I was trying to sway right-wing Christians. It's funny how your words won't sway if you only think you understand your audience)
Meanwhile, vastly more people died than necessary. Many more borders closed than necessary. We poo-pooed geometric increases in bureaucrats' authority. The aggregate risk increased much higher than it needed to be.