Revival of the heart
To stay awake at nights and praying to Allah (SWT) will help to revive the heart. The purpose of this act is to keep alive the heart. Having a living heart is only possible through prayers and thoughts. On the contrary a negligent heart is a like a dead heart. A person who is engaged in anti-God activities and bad deeds is worse than a dead person .
 Al-Moraqebaat by Mirza Jawaad Maleki tabrizi, Vol.1, Page 125.