I thought Muslims believed in a point system. So, anyone who gains more positive points than negative points will go to heaven, regardless of their affiliation.
The problem is that they generally agree on what is good and what is bad, but they don't know the NUMBER of points assigned to each thing.
So, the idea is that you had better try to do as many good things as possible and as few bad things, and you just have to hope that your points come out OK.
So, then, obviously, a non-Muslim is NOT going to be saying the correct prayers 5 times a day, so they don't get the positive points for that.
The question is: If you don't say the prayers, is that a zero (for non-action) or is that negative points?
If it's zero, then you can probably make that up with enough positive things. But if you are getting negative points 5 times a day throughout your life, it seems there is no way to do enough good to make that up.
So, there is the general concept, but the specifics are unknown.