Peace Gene,
Well looks like everybody else has pitched in and posted some good answers.
Yes, you had a team of the best and the brightest helping you today. Everyone did a very good job. Each had their own slant to what they said, but everything was still consistent across the board.
We do know that Allah(swt) is Merciful and that he is Just. We also knows he knows the innermost thoughts in our hearts, even before we do. We do know that all of these will be considered when we face judgement. We will be punished for our sins only to the extent punishment is warranted and we will be rewarded for our deeds many times beyond their worth.
If I remember right, most Muslims believe that there is a time of some degree of punishment for nearly everyone. Perhaps this is why it is important to have gradations of wrongdoing, becaue there is a corollary punishment, even if you are forgiven.
For instance, if I make up a story about my neighbor that I don't like and start spreading that around town, that is a pretty bad thing. There are probably some things worse, but it is also worse than a whole lot of other things, so after I die I can expect to be punished in a way that Allah sees as commiserate with the "crime". And even if I later realized how wrong this was and repent of it and try to make up for it, I can still expect to do some time in hell before being admitted to heaven. Am I right about this?
So at a Jr. High level of explaining.
Only the denial/blasphemy of acknowledging Allah(swt) through kufr or shirk is unforgivable.
No sins are more difficult for Allah(swt) to Him to forgive, all are forgiven just at his wish. When He wants something to be, it is.
We humans have to put forth more work to earn the forgiveness of sins. However, it is not our deeds that are capable of having sins forgiven.
There is no text book formula to say what needs to be done to be accepted as sufficient work to earns Allah(swt) forgiveness.
One man may be forgiven of murdering a hundred people simply by praying for forgiveness. Another man may not be forgiven for short changing his obligation for charity by one penny no matter haw many prayers he offers for forgiveness.
Continuing with the example of me bad-mouthing my neighbor...
A Christian doing such a thing would simply go to hell for all of eternity. A Christian can't lessen the time served in hell by their good works, because whether you deduct a minute or a million years from eternity, you still are left with eternity in hell. So for the Christian at the end of this life there are just two choices, either eternity in heaven or eternity in hell, everyone fits in one category or the other. There are no shades of grey inbetween.
But a Muslim can also have this sin off-set by the good he does and thus lessen the time to be served being punished. But for Muslims there are a million shades of grey, as varied as the lives that each person lives.
The part that is confusing is that, for the Muslim, on the one hand it is like Christianity in that it is all based on grace -- Allah does not have to let anyone in to heaven, but he loving grants it to all who he desires to grant it to. And those he does not grant it to can't say that he is wrong for not having done so.
But on the other hand, it is completely contrary to Christianity in that it is all based on works -- no one gets to heaven unless they have done enough good deeds to earn Allah's pleasure and avoided enough wrong to keep from incurring Allah's wrath. Where you end up depends on the balance sheet having more good marks than bad marks on your paper. This makes Allah, not a bestower of mercy but merely a good bookkeeper.
I'm having some trouble reconciling these two pictures that have been drawn for me with each other. I'm guessing that I've probably drawn one of them incorrectly, but I'm not sure which it would be, for I have heard both.