To believe in Risalat as to believe in Tauhid. We did not know about Allah. Allah, the merciful, has graciously sent the nabi-Rasuls (the holy oriohets) to us. They have introduced Allah to us. So, to disbelieve the Risalat is to disbelieve Allah. Therefore, to believe in risalat is an essential part of Iman. The delared of Tauhid has been made in ‘Kakima tayyiba’. In it by ‘la-ila-ha illalla-hu the declaration of Tauhid has been made and by ‘Muhammadur Rasulullah, the declaration of Risalat has been made.