Jaʿfar ibn Muhammad al-Sādiq, the sixth Imam, was celebrated by both Sunni and Shi’a Muslims for his piety, Islamic knowledge, and academic accomplishments. He was particularly most renowned as the initiator of Shi’a Islamic fiqh, called Ja’fari jurisprudence, as well as his extensive knowledge in a variety of fields which had a great academic impact on the people of his time. This article includes a brief biography of his life, his revered conduct, and his deep knowledge in jurisprudence; it also delves into the state of the Shi‘as during his time as well as his political confrontations with the Ghulat, or extremists, who held ideas that resulted from overstating particular Islamic beliefs. To eliminate the Ghulat beliefs from pouring into Shi‘a ideology and affecting its adherents, Imam Sadiq was compelled to confront them through refuting their ideology, declaring them as apostates, and demanding the Shi‘a to avoid their presence.