The necessity of sincere belief

وَلَوْ شَآءَ رَبُّكَ لَـَٔامَنَ مَن فِى ٱلْأَرْضِ كُلُّهُمْ جَمِيعًا ۚ أَفَأَنتَ تُكْرِهُ ٱلنَّاسَ حَتَّىٰ يَكُونُوا۟ مُؤْمِنِينَ

And had your Lord willed, those on earth would have believed - all of them entirely. Then, [O Muḥammad], would you compel the people in order that they become believers?