إِنَّكَ لَا تَهۡدِى مَنۡ أَحۡبَبۡتَ وَلَٰكِنَّ ٱللَّهَ يَهۡدِى مَن يَشَآءُ ۚ وَهُوَ أَعۡلَمُ بِٱلۡمُهۡتَدِينَ
Indeed, [O Muhammad], you do not guide whom you like, but Allah guides whom He wills. And He is most knowing of the [rightly] guided.
This ayah was revealed in a specific context.
Allah had granted the Prophet (peace be upon him) the favor of seeing many people from his family accept Islam: his daughters, his cousin Ali, his beloved wife Khadijah and his close friend Abu Bakr.
Yet most of his family had not embraced Islam. His uncle Abu Talib, who protected and looked after him and loved him dearly, never became Muslim.
This undoubtedly placed a heavy burden on his heart.
إِنَّكَ لَا تَهۡدِى مَنۡ أَحۡبَبۡتَ
Indeed, [O Muhammad], you do not guide whom you like.
This is not something within your authority.
وَلَٰكِنَّ ٱللَّهَ يَهۡدِى مَن يَشَآءُ
But Allah guides whom He wills.
This decision belongs to Allah alone.
وَهُوَ أَعۡلَمُ بِٱلۡمُهۡتَدِينَ
And He is most knowing of the [rightly] guided.
Here lies the secret. Allah best knows ٱلۡمُهۡتَدِينَ (those who are guided).
Guidance is not forced on anyone. It is offered to those who seek it sincerely and with an open heart.