From the early childhood Qoddus was a prodigy, and his intellectual and spiritual gifts were apparent. After completing his basic schooling in Bārforuš and Sāri at the age of twelve, he went to Mašhad to begin his religious studies there. At the age of eighteen, he left Persia for Karbalāʾ, where he joined Sayyed Kāẓem Rašti (d. 1844), the leader of the Shaikhi school. Qoddus studied with Rašti for four years. “He was the last to arrive, and invariably occupied the lowliest seat in the assembly. He was the first to depart upon the conclusion of every meeting. The silence he observed and the modesty of his behaviour distinguished him from the rest of his companions” (Zarandi, p. 72; see also Māzandarāni, 1944, p. 406). Shoghi Effendi (1897-1957) describes Qoddus as “erudite” and “the most esteemed disciple of Sayyid Kāzim” (Shoghi Effendi, p. 7).

After Qoddus finished his studies at Karbalāʾ, and on the way back to Persia, he, like other Rašti’s students, became a hermit and spent some time in contemplation and prayer in the mosque of the city of Kufa (Māzandarāni, 1944, p. 406; Amanat, p. 182). On returning to his native town of Bārforuš, Qoddus was welcomed and soon highly praised and supported by Šariʿatmadār (Māzandarāni, 1944, p. 406). This incited hostility of Šariʿatmadār’s rival, Shiʿite cleric Molla Saʿid Bārforuši, known as Saʿid-al-ʿolamāʾ (Māzandarāni, 1944, p. 406). All sources agree that Qoddus was a charismatic clergyman and that his piety and personal charm captured the admiration of every observer (Zarandi, p. 183; Māzandarāni, 1944, p. 406; Malek Ḵosravi-Nuri, p. 59; Amanat, pp. 183-84).

In May 1844, Qoddus was in Shiraz, where he met the Bāb and gave his full allegiance to the Babi faith. The circumstances of his conversion were as follows. One evening, when the Bāb was returning home accompanied by Mollā Ḥosayn (1814-1849), his first disciple, “there appeared a youth, disheveled and travel-stained.” That young man was Qoddus. He approached Mollā Ḥosayn, embraced him, and asked “whether he [Molla Hosayn] had found the Promised One.” At first, Mollā Ḥosayn tried to calm Qoddus’s agitation and advised him to rest for the moment, promising to enlighten him later. Then, on fixing his gaze upon the Bāb, Qoddus told Mollā Ḥosayn: “I can recognize him [the Promised One] by his gait.” Qoddus went on to say: “I confidently testify that none beside him [the Bāb], whether in the East or in the West, can claim to be the Truth. None other can manifest the power and majesty that radiate from his holy person” (Zarandi, pp. 69-70). Qoddus was the last person among the first eighteen people who embraced Bābism, and who were collectively designated by the Bāb as “the Letters of the Living” (Ḥoruf-i-ḥayy).

Since Qoddus was the last “Letter of the Living,” he was designated by the Bāb as “the Last Name of God” (Esm Allāh al-āḵer), just as Mollā Ḥosayn was distinguished as “the First Name of God“ (Esm Allāh al-awwal) by virtue of being the first “Letter of the Living.” The Bāb chose Qoddus as his traveling companion for the pilgrimage to Mecca in 1844. After Qoddus returned from the pilgrimage and tried to propagate Bābism, he became the target of persecution by the governor of Fārs and was expelled from Shiraz. Qoddus then traveled to Yazd, Kermān, Ardestān, Isfahan, Kāšān, and Tehran to propagate the Bābi religion, after which he returned to Bārforuš in 1847, where he stayed for the next two years.