Well, it seems that I must justify this idea that some non-believers get to enter Heaven, mainly for the benefit of HuntingMan and Nadiine.
The thing that strikes me, as I look around the world, that virtue is not the sole preserve of Christians. And vice is not the sole preserve of unbelievers. (And this is a fact that miltates against ebia's notion of transformation, by the way). So the thing is, would a just God ignore the vice of Christians, and the virtue of ubelievers, as He arrives at His determination for our various destinations in the hereafter? I cannot believe that He would, and I do not wish to be a part of a religion that preaches that He would. Justice is Justice.
To compound the issue, our beliefs are not voluntary. We can only believe what we think to be true, and the culture we are born into seems to be the determing factor, and not our conscious volition. The billion or so Moslems who pass their religion onto their offspring transmit more than just dry philosophy, but a vibrant, encompassing tradition and way of life. For them, to abandon their beliefs means abondoning much of their identity, and, not surprisingly, most of them choose to be who they are, rather than leap into the (comparitively) unknown that, to them, constitutes Christianity. Would a just God punish them for being born to a Moslem father and mother, in a Moslem community, in a Moslem state? I cannot believe that He would, and I do not wish to be a part of a religion that preaches that He would. Justice is Justice.
So, Nadiine, there you have it. You and I believe different things. My opinion may be opinion, but it is backed by at least the rudiments of reasoning. Furthermore, I am far from isolated in my 'opinion'. For example, it is the position of the Catholic Church that Heaven is not denied to some unbelievers. Do you really think the likes of the Buddha, or, more recently, Mahatma Gandhi, inhabit Hell? The distinction that Catholics like to make (and one I question) is that unbelievers may be saved in a religion, but are not saved by that religion.
Best wishes, 2ndRateMind.