Surah Ash-Shuraa — Ayah 8 (42:8)
وَلَوۡ شَآءَ ٱللَّهُ لَجَعَلَهُمۡ أُمَّةٗ وَٰحِدَةٗ وَلَٰكِن يُدۡخِلُ مَن يَشَآءُ فِي رَحۡمَتِهِۦۚ وَٱلظَّٰلِمُونَ مَا لَهُم مِّن وَلِيّٖ وَلَا نَصِيرٍ ٨
English translation (Saheeh International)
And if Allāh willed, He could have made them [of] one religion, but He admits whom He wills1 into His mercy. And the wrongdoers have not any protector or helper.
- - i.e., those who desire His guidance and His acceptance of them.
Brief commentary
If Allah willed to make them one nation on the religion of Islam He would have done so and entered them all into Paradise. But, His wisdom demanded that He enters whoever He wills into Islam and then enters him into Paradise. Those who wrong themselves by disbelief and sins, will have no one to protect them and no helper to rescue them from Allah’s punishment.