According to Imam Khomeini, the belief and concept of divine savior and reformer who would spread justice is considered to be a basic pillar of all divine religions.
The belief in the reappearance of the expected Mahdi (A.S.)the universal reformer is not confined to the Shia Muslims. Other Islamic groups and even non-Islamic groups like the Jews and the Christians and some of the great world intellectual figures believe in the appearance of a great spiritual reformer. In Psalm 37 is written: "...Trust in the Lord and do good; so you will dwell in the land, and enjoy security. ...For the wicked shall be cut off: but those who wait for the Lord shall possess the land. ...But the weak shall possess the land, and delight themselves in abundant prosperity.
...The Lord knows the days of the flawless, and their heritage will abide forever. ...For those blessed by the Lord, shall possess the land, but those cursed by Him shall be cut off. ...The righteous shall possess the land, and dwell upon it at peace for ever..."
The Qur'an and belief in al-Mahdi In the Qur'an a time is promised when the worshippers of Truth, the world's people of righteousness, will take over the power and government of the world, and the glorious din of Islam will reign all over the earth. Other ayahs have been revealed which exegetically point to Hazrat Mahdi (A.S.). "For We have written in the Psalms, after the Remembrance, 'The earth shall be the inheritance of My righteous servants." (XXI; 105) "Allah has promised those of you who believe and do righteous deeds that He will surely make you successors in the land, even as He made those who were before them successors, and that He will surely establish their religion for them, and will give them in exchange, after their fear, security: They shall serve Me, not associating with Me anything.
" (XXIV:55) "It is He Who has sent His Messenger with the religion of truth, that he may lift it above every religion, though the unbelievers be averse. (LXI:9) "Yet We desired to be gracious to those that were abased in the land, and to make them leaders, and to make them the inheritors. " (XXII:5) The above ayahs clearly show that in the end the world will fall to the hands of Allah's worthy and righteous servants and that they will become the leaders of the people of the world. Then Islam will be victorious over all religions. Belief in al-Mahdi and the Sunni authorities In this subject, the scholars in the Sunni school have related many hadiths from the Prophet of Islam, through narrators whom they themselves trust.