Sincerity (Ikhlas) in worship is essential in Islam as it ensures that acts of devotion are done solely for Allah’s pleasure, without seeking worldly recognition or reward. The Qur’an emphasizes: “And they were not commanded except to worship Allah, [being] sincere to Him in religion…” (Qur’an 98:5). Sincerity purifies intentions, brings acceptance of deeds, and strengthens the believer’s connection with Allah.