How does a person believe in other parts of the world he did not see?
He simply relies on information and believes in that. A believer is informed by Rasulullah (Sallallaahu Alayhi Wasallam) of the existence and Oneness of Allah. He believes in the information given by the Prophet (Sallallaahu Alayhi Wasallam). Furthermore, the entire world is a manifestation of the power of Allah. Consider the alternating of the day and night. The rising and setting of the moon and stars. Who controls all these? None other than Allah.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai