On a more optimistic note, the Rambam mentions that even רשעים who have more sins than Mitzvot, still have a share in the world to come. He also says that חסידי אומות העולם, righteous Gentiles, have a share in עולם הבא.
However, says the Rambam in chapter three of הלכות תשובה, that there are certain individuals who will not have a share of the next world, because their level of evil is absolutely intolerable.
He lists about twelve categories of such despicable human beings. I will describe them in the coming days.
The top three are מינים, אפיקורסים, and כופרים.
The מינים are deniers in the existence of G-d. Or they believe that G-d does not supervise the world or that there is more than one G-d. Or, he may believe that G-d has a physical form, or he may worship the stars as an intermediary. All of these are מין.
The אפיקורס does not believe that Hashem communicates with man, and does not believe in prophecy. He does not accept the prophecy of Moshe Rabbeinu. And he does not believe that Hashem knows the thoughts and actions of man. This is an אפיקורס.
The כופרים are deniers. The כופר בתורה does not accept that the Torah is from Hashem. Even if he denies one word of the Torah is not from Hashem, he is a כופר. If he says that Moshe made things up and they were not from Hashem, he is also a כופר.
We begin to see why these individuals have a different status than everyone else. More tomorrow, G-d willing.