Even if the entire duration of the world’s existence has already been exhausted and only one day is left before Doomsday (Day of judgment), Allah will expand that day to such a length of time, as to accommodate the kingdom of a person out of my Ahlul-Bayt who will be called by my name. He will then fill out the earth with peace and justice as it will have been full of injustice and tyranny before then. Sahih Tirmidhi along with 24 other Sunni sources
This narrative is very similar to those of Shiites but Sunnis think that Imam Mahdi (AS) is not alive and it may not be born yet. We on the other hand say that Mahdi (AS) is alive and he is son of Imam Hassan Askari (AS) the 11th Imam of Shiites. This confirms the above narrative that emphasizes Imam Mahdi is from Ahlul-Bayt.
Today I read a narrative that shows Jesus will pray behind Mahdi (AS)
Imam Sadeq (AS) Said:
One day, prophet Muhammad came to his companions with happiness and smiles. People said: Allah keep you happy and augment your euphoria(tell why you are happy).
Prophet (PBUH) said: There is no day nor night but rather I receive a gift from God and today indeed my Lord gave me a gift that never gave like it before: Gabriel came to me and delivered greetings of my Lord and told me: Oh Muhammad, Allah (mighty and the majestic) chose seven people among tribe of Bani Hashim who no one like them created in the past nor in the future; (they are) You Messenger of Allah, the master of prophets, and Ali ibne Abitalib, your executor master of executors, and Hassan and Hussein your grandchildren master of grandchildren, and Hamze your uncle master of martyrs, and Ja’far your cousin that fly everywhere in heaven with angels, and excelency Qaem that Jesus son of Mary will pray behind him when the Lord descend him to the earth. And he is of the race of Ali (AS) and Fatima (SA) and children of Hussein (AS).
Source: Rozat o AlKafi, Narrative 10
 Qaem is a name of Mahdi (as).
Mahdi (AS) is the 12th Imam of Shia Muslims. He is invisible since 255 Hejri-Ghamari (about 1176 years).
He is alive and will be appeared to spread justice in the earth and destroy the roots of cruelty.
He is descendant of prophet Muhammad (PBUH), He is innocent, He is the complete human, He is the owner of our time, He is Mahdi i.e. “The guided one”.
Many people are waiting for him, but there are a few ones who know him as is.
I love him. I’m praying for his health and appearance.
This blog is to introduce Mahdi to the world, God willing.
This is a copy from blog Imam Mahdi (aj) : Read Main Article