Given the fact that the ins titution of prophethood is central to the religion of Islam and is its second creedal principle, using a method that is descriptive and analytical, this paper sets out to examine the reasons that are used for the proof of prophethood by the Maturidi and Imāmīya schools, which are two of the great schools of Islamic creedal theology and prophetology within Islam. An examination of the proofs proffered by the two theological schools yields the conclusion that the institution of prophethood is a phenomenon whose reality is undeniable both on rational and scriptural grounds. The two schools prove the principle of the commissioning of prophets [by God] by use of various principles and axioms. It will also be seen that both schools are in agreement that mankind can attain to an understanding of certain matters by putting his rational faculty of understanding to use, but that the understanding of many other matters are outside the ability of this faculty. The Imāmīya consider the principle of grace to be the best reason for the commissioning of prophets on the part of God, but they do not consider man’s faculty of rational intellection (‘aql) on its own to be a sufficient authority (hojjat) that can be used to justify punishment [in the hereafter]. Contrarily, the Maturida consider reason to be a sufficient authority (hojjat) for the justification of such punishment, and consider the commissioning of prophets as a necessary component in ensuring that the duty of care is properly provided and executed (e’temām-e hojjat). The Noble Quran emphasizes the role of the prophets as being one of immaculate persons who have been commissioned from on high in order to solve the various problems which mankind faces which have arisen in the absence of prophets, and for the purposes of resolving these differences. The Noble Quran also characterizes the role of prophets as being divine agents who channel God’s will and convey His message and ordinances and divine dispensation to mankind, and then act in the capacity of unimpeachable authorities (hojjat); thereby completing the duty of care and thus completing the argument in the case that is being prepared for use on the Day of Judgement (e’temām-e hojjat) against anyone who fails to abide by God’s revealed will, ordinances and divine dispensation which were conveyed to mankind by God’s prophets.