Many people ask what is the use of an Imam that can not be seen. Just as the sun is still of use to us even when it is hidden behind the clouds, Imam (A) is of benefit even when hidden.
Although we can not see our 12th Imam, Imam Muhammad al-Mahdi (A) can see us. He is aware of our prayers, deeds actions and troubles. Any believer who truly asks him for help receives his assistance.
The ghaybat (concealment) of Imam (A) is in two stages:
Ghaybate sughra - minor concealment.
Ghaybate kubra - major concealment.
Ghaybate sughra started from after Imam (A) led the funeral prayer of his father (Imam Hasan al-Askeri (A)) until the death of his 4th deputy. All in all 68years.
Ghaybate kubra started from the death of his 4th deputy till this day.
During Ghaybate sughra although the Muslims could not see Imam (A) they could communicate with him through his deputies:
Uthman bin Said
Muhammad bin Uthman
Husain bin Rauh
Ali bin Muhammad Samry.
During Ghaybate kubra although there are no special deputies. The Mujtahids are his representatives.
There have been many examples in history of where Imam (A) has guided and helped his followers:
There once lived a great Mujtahid named Allama Majlisi. Once this Mujtahid was asked what to do with the body of a pregnant woman who had died. Should the dead woman be buried as she was or should she be cut open and the child removed, then the woman buried.
Allama decided that the woman should be buried as she was, with the child.
When the people were carrying the coffin to the grave, a horseman appeared and said that Allama had decided that the baby should be removed. This was done.
A few years later Allama Majlisi was visited by a man with a small child. The man told Allama that this was the same child that had been cut from his mother after Allama had sent the horseman telling the people that he had changed his instructions.
Allama immediately realised that the horseman must have been Imam Muhammad al-Mahdi (A) who had come to his help, preventing him making a grave mistake.
From that day Allama stayed in his house refusing to give anymore advise to the people, in case he made another mistake. In a few days he received a letter from Imam (A) telling him that he should not worry and should continue to guide the people. If by any chance he made a mistake Imam (A) would come to help him rectify it.
The duties of each and every Muslim in the time of Ghatbate kubra is:
To be the caretakers of Islam.
To pray for the safety of Imam (A) and give sadaqa for his safety.
Ask Allah to make Imam (A) appearance soon, so that he may come and fill the world with truth and peace.
Whenever the name of the12th Imam is said, you should stand, placing your right hand on your head and bow your head. You should also recite Salawaat after his name.
Moral:
The Holy Prophet (S) has said that if someone dies without knowing the Imam (A) of his time, his death is that of an unbeliever. We must therefore carry out our duties to our 12th Imam who is still alive and in Ghaybate(concealment).