Obligation to fight and die.

Qur'an 9:38 "Believers, what is the matter with you, that when you are asked to march forth in the Cause of Allah (i.e., Jihad) you cling to the earth? Do you prefer the life of this world to the Hereafter? Unless you march, He will afflict and punish you with a painful torture, and put others in your place. But you cannot harm Him in the least."