According to al-Shahid al-Thani in Haqa’iq al-Iman ...

According to al-Shahid al-Thani in Haqa’iq al-Iman , almost all Muslim scholars believe that it is not permissible to follow other people in the principles of the religion [ Usul al-Din ] [6] , because the belief in such principles should be with certainty, but following other people does not provide one with certainty [7] .

Al-Shaykh al-Ansari, in his al-Rasa’il , emphasizes that the mere presumption of the foundational principles of the religion [ Usul al-Din ] is not enough for one to be regarded as a true believer [8] . Based on numerous hadiths that highlight the necessity of understanding, he argues that a believer is obligated to seek knowledge of these principles and strive to attain certainty regarding them, to the extent that such understanding is possible [9] .

Therefore, understanding the Usul al-Din is essential for every Muslim who wishes to strengthen his or her Shia belief. An Overview of Usul al-Din Meanwhile, these five foundational principles ( Usul al-Din ) are explained as follows: Tawḥīd – The Oneness of God At the heart of Shia belief lies Tawḥīd—the absolute Oneness and Unity of Allah. It is not only the first of the Usul al-Din but also the essence that gives meaning to every other principle of faith.

Tawḥīd means affirming that God is One in His essence (dhāt), attributes (ṣifāt), and actions (afʿāl). His essence is indivisible; His attributes are not separate from His essence [10] ; and all actions in existence ultimately originate from Him alone. He has no partner, no likeness, and no rival. The Qur’an declares this truth most concisely and profoundly: Say, ‘He is Allah, the One. Allah is the All-embracing.

He neither begat, nor was begotten, nor has He any equal.’ (Qur’an 112:1–4) In this regard, Shaykh al-Muzaffar in his The Faith of the Imamiyyah Shi’ah , writes: “Hence, the existence of these Attributes is the same as the existence of His essence. For instance, Almighty Allah’s Omnipotence with respect to His existence is the same as His Ever-livingness, and His Ever-livingness is as same as His Existence.

[11] “ This comprehensive understanding distinguishes Shia belief in divine unity from a purely abstract notion of monotheism. It calls believers to see Allah as the only true source of power, sustenance, and mercy. In practical terms, Tawḥīd shapes the believer’s inner world. When one truly affirms that only Allah controls all affairs, fear of creation diminishes and reliance on God grows.