This is in the Quran 10: 44
إِنَّ اللّهَ لاَ يَظْلِمُ النَّاسَ شَيْئًا وَلَكِنَّ النَّاسَ أَنفُسَهُمْ يَظْلِمُونَ
The explanation:
(God wrongs not people in anything, but it is people who do wrong themselves.)
And there are a large number of the ayat in the Quran indicating the same meaning.
All people are sinners, but sins differ in their seriousness; whether the sinner is intending or by mistake; does he insist on the sin, or does he regret? Is the sinner associating with God, or is he a monotheist that does not associate anyone or anything with God? Is the sin concerning some wrong-doing against other people or only to himself? Is the sin concerning a major disobedience of the Ten Commandments, or it is some minor thing between man and his Lord, …etc.
Moreover, God – be glorified – is Clement; He gives them respite that they would repent and desist from their atheism and transgression; and He postpones their punishment.
This is in the Quran 16: 61
وَلَوْ يُؤَاخِذُ اللّهُ النَّاسَ بِظُلْمِهِم مَّا تَرَكَ عَلَيْهَا مِن دَآبَّةٍ وَلَكِن يُؤَخِّرُهُمْ إلَى أَجَلٍ مُّسَمًّى فَإِذَا جَاء أَجَلُهُمْ لاَ يَسْتَأْخِرُونَ سَاعَةً وَلاَ يَسْتَقْدِمُونَ
The explanation:
(If God should take men to task for their evildoing, He would not leave on [the earth] one creature that moves;
but He is deferring them to a term stated [: He postpones their punishment to the world of souls following their death];
and when their term [: their hour of death] is come they shall not put it back by a single hour nor put it forward.)
It means: none can delay their hour of death or bring it earlier, even for one hour.