Allah says:
[وَلَوْ شَآءَ
اللَّهُ لَجَعَلَكُمْ]
(And had Allah willed, He would have made you) meaning - O mankind,
[أُمَّةً
وَحِدَةً]
((all) one nation,) This is like the Ayah:
[وَلَوْ شَآءَ
رَبُّكَ لآمَنَ مَن فِى الاٌّرْضِ كُلُّهُمْ جَمِيعًا]
(And had your Lord willed, all of those on earth would have believed
together.) [10:99], meaning, He could have created harmony among them, and there
would not be any differences, conflicts or hatred between them.
[وَلَوْ شَآءَ
رَبُّكَ لَجَعَلَ النَّاسَ أُمَّةً وَاحِدَةً وَلاَ يَزَالُونَ مُخْتَلِفِينَ
]
[إِلاَّ مَن رَّحِمَ
رَبُّكَ وَلِذلِكَ خَلَقَهُمْ]
(And if your Lord had so willed, He would surely, have made mankind one Ummah
[nation or community], but they will not cease to disagree. Except him on whom
your Lord has bestowed His mercy, and for that did He create them.) (11:118-119)
Similarly, Allah says here:
[وَلـكِن يُضِلُّ مَن
يَشَآءُ وَيَهْدِى مَن يَشَآءُ]
(but He allows whom He wills to stray and He guides whom He wills. ) Then on
the Day of Resurrection, He will ask them all about their deeds, and will reward
or punish them even equal to a scalish thread in the long slit of a date stone
or the size of a speck on the back of a date stone, or even a thin membrane of
the date stone.