Faith is an essential character of a Muslim. In order to become a Muslim, a person must have faith in One God, his Prophets, Books, angels and Aakhirah.
In this video the preacher has beautifully tried to explain the huge reward a believer will get for having faith in the unseen.
Prophet (pbuh) was the most compassionate and kind towards his ummah and he prayed for more blessing and goodness especially for those who believed in him and followed him without seeing him.
It was narrated from Anas ibn Maalik (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said:
“Glad tidings to the one who believed in me and saw me, and sevenfold glad tidings to the one who believed in me but did not see me.”
Narrated by Ahmad in al-Musnad (3/155).
The Prophet (peace and blessings of Allah be upon him) also gave glad tidings to the believers who came after him and did not see him, that they would see him at the Cistern (al-hawd):
It was narrated from Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) went out to the graveyard and said:
“Peace be upon the abode of believing people, and if Allah wills we will join you soon. Would that I could see our brothers.” They said: Are we not your brothers, O Messenger of Allah? He said: “You are my companions. Our brothers are those who have not come yet. I will reach the Cistern before them.” They said: O Messenger of Allah, how will you recognize those of your ummah who came after you? He said: “Do you not see that if a man has a horse that has a white blaze and white feet among horses that are all black, will he not recognize his horse?” They said: Of course. He said: “They will come to me with bright faces and limbs (like the white markings of a horse) because of the traces of wudoo’, and I will reach the Cistern before them.”
Narrated by Muslim (249), al-Nasaa’i (150).