Therefore, the first thing people should know if they are waiting for Imam Mahdi to come is that they need to get to know him. The more people get to know Imam Mahdi, the more they realize his value and greatness and this will cause their thirst for seeing him become even more.
Therefore, people should act like those who are expecting someone, before they could display such a claim. We cannot consider someone as a lover of Imams and prophets only because he says so. People should prove this with their actions.
Therefore, it is obvious that someone who is waiting for Imam Mahdi should be prepared for his return every second. That is, he becomes happy any time he hears the news of Imam Mahdi’s return and is prepared to aid him, and sacrifice his life and properties for him. The one who is really waiting for Imam Mahdi is neither a sinner, nor is attached to any worldly matters. Because if he is, he can never forget about his attachments and sins overnight and fight for Imam Mahdi’s sacred purpose.
source : tebyan