بسم الله الرحمن الرحيم
One of the conditions of the reappearance 
of the Imam Mahdi (a.s.) is social and global readiness. Before the reappearance of the Imam of Time, tyranny, oppression and injustice permeate the world; bloody wars are fought among nations and countries, and the earth is crammed with dead bodies. Imam Sadeq (a.s.) says: “The Imam of Time shall not reappear unless two third (2/3) of the people are killed.” Then he was asked: “How many people will survive?” The Imam said: “Are you not pleased to be of the one third (1/3) of the remnant?”
During that time, there will be no security for the lives and property of people. The roads are unsafe; fear and horror will permeate the society; there will be sudden deaths throughout the human society. Imam Ali (a.s.): There are signs for the reappearance of Mahdi (atfs) including extensive and remorseless killings, fast and consecutive deaths and spread of epidemics.
According to the narrations, during that age, the innocent children will be killed in the most brutal way by the oppressive rulers. Deadly diseases will spread all over. In such a difficult circumstance, hopelessness will engulf the society and death will be regarded as the best divine gift, and the only wish of the people would be to die. In that time, the people will yearn for death due to brutality and aggressions.
In such a circumstance in which the hearts of the people turn towards Allah are prepared for the universal revolution and this heavenly glad-tiding echoes outs in every nook and corner of the world: ‘O people of the world, the time of the reign of the tyrants have come to an end and Mahdi has reappeared. This heavenly call once again blows a new spirit into the body of people making their lives full of love, faith, liveliness and vigor.
Thus, one of the conditions necessary for the reappearance of the Imam of Time (may Allah hasten his reappearance) is social preparation which means that when the people get tired of injustice, tyranny and the available systems in the world and they taste the bitterness of the material life in a way such that despair and hopelessness take all over the world and people become prepared for a faith-based revolution. In such a circumstance, the Imam of Time (a.s.) will reappear.
(Courtesy: Imamalmahdi.com)
MAHDAVIYAT 