Because of the issue Satan raised in connection with Jehovah’s sovereignty. Satan claims that no one serves God out of a willing heart.
بِسَبَبِ ٱلْقَضِيَّةِ ٱلْمُتَعَلِّقَةِ بِسُلْطَانِ يَهْوَهَ ٱلَّتِي أَثَارَهَا ٱلشَّيْطَانُ .‏