Hmm. I would say it's more we need God's grace to be good, so it's not exactly getting what we deserve. I understand there is pardon and mercy from God, but that has it's appropriate place. Usually virtues if applied everywhere universally warp and don't become virtues anymore. It becomes an extremism.I'd like to pursue this a bit more if you don't mind.
I know very little about Islamic beliefs, so I'll let you instruct me on that, but just taking what you are saying, it seems that you favor a system where everyone gets exactly what they deserve (in terms of rewards and punishment), no more, no less. Are sure you want that though? Do you want to receive exactly what you deserve? You might regret it. Is anyone totally good, or totally bad?
I prefer a model of God that involves a lot of caring and a big dollop of mercy. Looking at the parable of the Prodigal Son (yes, that's Christian theology) the father (a metaphor for God) rejoices over the "bad" son that repents and (gently) rebukes the "good" son who feels that he is being unfairly treated. I see it slightly differently, rather like we are all struggling in the mud, though some do better than others, and we all need help.
(Note: I'm presenting this from a theist viewpoint, though I am not a theist. Nevertheless, I think it applies to how we treat each other).
There is a proper place to exact justice and vengeance and a proper place to forgive and have mercy.
I think it's unbalanced to dismiss justice and vengeance as not virtues in anywhere shape and from. In the wrong application, they are ugly.
I think God giving everyone slack is an extreme version of mercy that is no longer virtuous.