In the Name of Allah, the Most Beneficent; the Most Merciful!
Oh Allah, be upon your last representative, our twelfth Imam, Hojjat ibn al-Hasan, may your peace be upon him and his forefathers, at this time and at all times, his master and his protector, his leader and his helper, and his guide and his guardian, until you place him on your earth, so that you may guide him in making use of this, for a great deal of time to come.
When we look into the scriptures of the different divine religions, they share a unique approach, which has made a hopeful future for the human race. With different levels of emphasis, all have made reference to a savior; who will spread justice throughout the world. In contrast, sociological and non-divine methodical approaches are more pessimistic, and they indicate that the fate of the human race will deteriorate. They believe that wars, outbreaks of violence, and bombardment upon the innocent will escalate as time progresses.
The Qur’an, as the last and most complete divine scripture, mentions the promise of the fate of the earth and the people:
Surah 21 (Anbya), Ayeh 105; “Indeed we wrote in the Psalms (Zaboor) after the reminder, ‘my righteous servants shall inherit the earth.’”
Surah 7 (Aa’raf), Ayeh 128; “For sure, the earth belongs to Allah to give as an inheritance to such of his servants as he pleases, and the best of the end belongs to the righteous.”
Surah 28 (Qassas), Ayeh 5; “And we wish to be gracious to those who were forced to weakness on the earth, to make them leaders, and make them heirs.”
Surah 24 (Noor), Ayeh 55; “Allah has promised those among you who have come to believe, and perform good deeds, that he will certainly grant them representatives on the land, just as he has granted it to those before them; and that he will establish with authority, their religion, which he has chosen for them, and that he will change their state of fear in which they live in, to one of security and peace. ‘They will worship me alone, and will not associate anything with me, and if anyone disbelieves after this, they are impious.”
The Prophet of Islam (S.A.W.) signifies this heavenly messiah in a more descriptive manner, “If there were only one day remaining until the end of the world, God would elongate that day so that he will raise a man from my progeny whose name is my name, and whose konya (nickname) is the same as mine. He will spread justice through the face of the earth, as it has been corrupt and full of injustice.” The man described is whom we know to be Imam Mahdi, the 12th and final infallible successor of the Prophet. He will arise and accomplish God’s promise. The Prophet has stated, “Anyone who denies the reappearance of Imam Mahdi has become a disbeliever.”
Who is Imam Mahdi? In a variety of different Hadiths or narrations, Imam Mahdi (A.S.) has been well introduced by the Prophet and all of the Imams:
Imam Mahdi is of the progeny of Prophet Mohammad and the A’emmeh, and there are approximately 389 Hadiths verifying this. There are 48 Hadiths stating that Imam Mahdi resembles Prophet Mohammad more closely than anyone else in history; and his name is the Prophet’s name.
214 Hadiths indicate that he is a direct descendant of Imam Ali.
There are 192 Hadiths, shared by both Shi’as and Sunnis that Imam Mahdi is a direct descendant of Fatima-tuz-Zahra (S.A.). As stated in 160 Hadiths, he is the descendant and the ninth Imam after Imam Hossein (A.S.).
His father’s name is Hassan, as indicated in another 147 Hadiths.
In addition, 146 Hadiths mention that he is the son of the 11th Imam, Hassan Askari (A.S.)
136 Hadiths tell us that Imam Mahdi is the 12th and final Imam, and there will be no successor to him, with another 127 Hadiths stating that he will spread justice throughout the world, as it has been filled with corruption.
According to 91 Hadiths, there is a long absence for the Imam which will end when God permits.
10 Hadiths reveal that he has two absences.
Imam Mahdi has a very long life, as stated in 318 different Hadiths.
To further familiarize ourselves with Imam Mahdi, I would like to elaborate on the events prior to his birth.
Governors of the time knew that the son of the 11th Imam (Imam Hasan Askari) would be the seal of the Imams, and the one who is destined to accomplish the divine task of spreading peace and justice to the world. Knowing this, they demanded to have Imam Hassan under house arrest in a military base, named Al-Askar, located in the city of Samera, in present-day Iraq; resulting in the laghab of Askari which was added to his glorious name. Female spies assigned by the government searched homes inside the military base, to investigate whether or not any women were pregnant, with the goal of finding the prospective son, to kill him before his birth. However, the non-believers were unaware that God Almighty has unlimited powers. Much like the way he placed Prophet Moses into the arms of the Pharaoh to be raised in his own palace, Imam Mahdi, who had a much greater responsibility than Moses, would be born regardless of any struggle of the enemies. Nargis Khatoun, mother to the final Imam, was pregnant, with no signs of being such.

Birth
Born on the 15th of Sha'ban in the year of 255 Hijri, Imam Mahdi (A.S.) would soon become the religious leader of the land following the death of the previous Imam, his father, which occurred in the year 260. Therefore, Imam Mahdi reached his position of Imamat at the age of five. Questions may rise regarding how a child of such an age could possibly become an Imam. The obvious answer to this question would date back to when the Prophet Jesus (Eesa, A.S.) was born. As you may recall, the Prophet spoke once he was born, telling the people around him that God had already assigned him to the position of Prophet-hood. Therefore, for Imam Mahdi, who is to bear such a great responsibility, greater than all preceding Prophets and Imams, any age which God specifies is appropriate for his Imamat, since this position is a divine status which is independent of age, and there is precedence to this, among Prophets and Imams.

Disappearance (Ghaibat)
In the year 260, Imam Mahdi, by the order of God, began the stage of disappearance after completing the ceremonial prayer for the funeral of his father. Therefore, people were no longer able to present their problems or questions directly to the Imam. From the year of 260 to the year of 329 Hijri, four specific and special representatives, or Naibs, were set to send the messages to and from the Imam between him and the people. This time period of 69 years is known to be the Ghaibateh Soghra, or the short absence. The Naibs came in sequential order. These humble people were known to be "Novvaabeh Arba'eh." The first of which, was Jenabeh Othman-ibn Saeed Amri. The second, his son, was Jenabeh Mohammad-ibn Othman Saeed Amri. After him came Jenabeh Hossein-ibn Rouh Noubakhtee, and the last being Jenabeh Ali-ibn Mohammad Saymori. One week before the death of the fourth and last Naib, there was a special letter (towqi'a), issued by Imam Mahdi to Saymori himself, stating:
Ya Ali-ibn Mohammad, you will pass away from this world within a week; do not assign anyone after yourself, to the position that you have been assigned. It is because this position will no longer be available, and after your death, the Ghaibateh Kobra will initiate.
Once the fourth representative had passed away, the long absence, or Ghaibateh Kobra, began. Since the era of Ghaibateh Kobra began, we Shi’as pray for the reappearance of the Imam, who will bring upon the world absolute peace, prosperity and justice.

Meaning and purpose of Ghaibat
The Ghaibat (or occultation) of Imam Mahdi means that he either is isolated from the rest of the world’s population, or he lives among them and as stated in hadith, “He walks in the markets, sees the people and knows them, yet they see him and do not recognize him."
The purposes of his disappearance, as partially stated in hadiths, include safeguarding him from his enemies, freeing him of any obligation (Bai'at) before any government – which for years hindered the progress of a number of his predecessors – and giving him the means of preparation for his grand and glorious responsibility to govern the whole world and bring peace and unity to mankind. More concise reasons of the Imam's disappearance, as mentioned in ahadith, will be better understood once he reappears. It is noteworthy to say that "Ghaibat" or disappearance has roots in the Qur'an, where it is stated that belief in this concept is a provision of piety.

Longevity
The longevity of Imam Mahdi (A.S.) may raise questions for some people. How do we celebrate his 1167th birthday now? Is it possible for someone to live that long? The responses are:
1- God, who has created all, is capable of doing anything he desires. Though some of it may be unclear to us, through reasons he seems fit, he has given the order of the longevity of our savior, so that he may appear at the right time. 2- Life is a principle; life is the basis; while death is adventitious. You never ask anyone why he or she is alive. You do not ask for a reason why people live, while death needs a cause. When you hear that someone has passed away, the first questions that come to mind are: "Why?” "By what reason?” and "How?" So, death is an effect. If someone knowingly avoids the causes resulting in death, he or she can certainly live as long as possible. Imam Mahdi, who is the last Godly resource, has been given such knowledge by Almighty Allah, and is well aware of how to avoid such issues, and is protected by Allah as well, so, he can live as long as needed.
3- Examples of longevity among many different divine representatives in the past indicate that long life is not unusual. For instance, prophet Nooh (Noah) lived 2500 years. As the Qur'an states, he was prophet for his people for 950 years before the flood. Among more recent examples, we know Salman Farsi, who lived for 400 years.
According to the Qur’an, Surah Nisa, (4: 159) Prophet Eesa (Jesus) is still alive, and the belief of his existence is a part of the basic principles of Islam.
Imam Mahdi (A.S.) as Hadiths say, has similarities to different prophets; his similarity to Prophet Nooh is his longevity. Also, ahadith educate us that in spite of his long life, the Imam has a young face, resembling that of someone less than 40 years of age.
Oh Allah, expedite the re-appearance of Imam Mahdi; give us the chance to better serve him and enable us to perform our duties appropriately.