Those who have been warned by other people,  "Behold, a host has gathered against you; so beware of them!" - whereupon this only increased their faith, so that they answered, "God is enough for us; and how excellent a guardian is He!"

3:173 Al Quran

Hadhrat Amr Bin A’s (radiallahu anhu) narrates that Rasulullah (sallallahu alayhi wasallam) said:

“The heart of man lingers after everything. Allah does not care for a man who puts his heart at the disposal of everything; he may be destroyed in any place (and way – Allah, cares not for him). Who ever has trust on Allah, Allah suffices for him in all affairs.” 

(Ibn Majah)