Allāh sent Messengers to call people to worship Him alone, without associating any partners with Him. This ensures that mankind has clear guidance and cannot claim ignorance as an excuse. As stated in the Qur’an:
“And We certainly sent into every nation a messenger, [saying], ‘Worship Allāh and avoid Ṭāghūt (false deities).’”
— Surah An-Naḥl (16:36)
Additionally, the Prophet Muhammad (peace be upon him) emphasized the importance of exclusive worship for Allāh, teaching that His right upon His servants is that they worship Him alone and associate nothing with Him. This is highlighted in the hadith where the Prophet said:
“Do you know what Allāh’s right upon His servants is? It is that they should worship Him alone and not associate anything with Him.”
— Sahih al-Bukhari 7373
These teachings highlight the essential message delivered by all Messengers: to affirm worship for Allāh alone, guiding mankind to direct all acts of worship exclusively to Him.