I'm not sure whether Cho was an athiest or not. A vast majority of people believe in a Supreme Authority. In his suicide note, he mentions "saving the opressed, etc. etc." so he had some visions of...
Seung-Hui Cho was born on January 18, 1984 and died on April 16, 2007. Seung-Hui Cho would have been 23 years old at the time of death or 28 years old today.