1. The historical knowledge about the existence of Imam Mahdi. Information like he being the twelfth Imam, his birthday, etc.
2. Getting to know the spiritual position of Imam Mahdi. Not everyone could have this knowledge and it takes much capability. As a matter of fact, Imam Mahdi’s special companions are those who know about the spiritual position he has.
We could read Ziarat Jame’e prayers in order to get to know the greatness of the position of Imams.
More than that, reading authentic books written about Imam Mahdi could make one familiar with the position and greatness of Imam Mahdi to some extent.
Waiting for Imam Mahdi to return is the best thing every Muslim could do, and it is said to be the best prayer. Those who are waiting for Imam Mahdi have a high position and even if they die, they will be rewarded like those who fight for Imam Mahdi after his return.
source : http://www.tebyan.net
