The most beneficial and highest-ranking of sciences is the knowledge of what a servant owes his Lord: the Oneness of God in His Lordship, His Names and Attributes, and His Divinity. For this purpose, God created humankind, sent messengers, and revealed scriptures. The science of Tawhid (monotheism) is the noblest and most excellent of all sciences, for it is God's right upon all His servants. This is why He created His servants with an innate inclination to acknowledge it.
However, the devils lead them astray from the straight path, causing them to stray into what contradicts and opposes it. Therefore, it is essential to know what contradicts and opposes this Oneness, namely, associating partners with God, the Exalted and Majestic. This is why we see God, the Glorified and Exalted, frequently mentioning Tawhid alongside its opposite. He has stipulated that the validity of Tawhid requires avoiding Shirk (associating partners with God). Similarly, God, the Blessed and Exalted, has stipulated that the acceptance of deeds, entry into Paradise, and forgiveness of sins require avoiding Shirk. He has also stipulated that whoever hopes to meet Him must not associate anything with Him. This book contains the complete history of this subject from the time of the Prophet Noah, peace be upon him, until our present day. The application works without internet, has a night mode feature, saves the page and book in a comprehensive format, and has the ability to search by subject.