One has to believe in the message of our Prophet Muhammad, salla-l-lahu ^alayhi wa sallam, and that he is the seal of Prophets, i.e., he is the last of them. Allah ta^ala said in Surat al-’Ahzab verse # 40:
﴿وخاتم النبيين﴾ سورة الأحزاب.
The verse means: “… and last of the prophets.”
The Prophet, salla-l-lahu ^alayhi wa sallam, said :
“وخُتم بي النبيون” رواه مسلم
This means: “…and the line of prophets is closed with me,” narrated by Muslim.
One has to believe that our master Muhammad, salla-l-lahu ^alayhi wa sallam, is the master of all the offspring of Adam, and that is agreed upon by the scholars. It is derived from the hadith narrated by at-Tirmidhiyy [in which the Prophet, salla-l-lahu ^alayhi wa sallam, said:
“أنا سيد ولد ءادم يوم القيامة ولا فخر”
This means: “I am the master of Adam’s offspring in the Hereafter and it is no boast” i.e., he is not saying that for pride, but to speak about Allah’s grace.