Like all good religions, this is not just philosophy but magic. Moses parts the red sea. Jesus turns water to wine and raises the dead. By succumbing to the wishes of the island, all good things can happen.
Look: I never expected every single detail, or even most of them, to be explained or even acknowledged in the finale. Homer is allowed to nod. I just wish he didn't say, "Night, all" and head off to bed.
The Lost finale was a tragedy, a genuinely uninvolving and downright dull botch that not only fails as a stand-alone episode and fails as a finale, but lessens the dramatic impact of the last six years.
Having watched Lost faithfully throughout its run and marveled at the twists and turns, however odd and fanciful, I couldn't help a sense of revulsion at the easy way out the writers took in the show's finale.