Automatically Win Mission
Drop to the console during the game with the ` key and type: 

srv_success 1 

All objectives will be successful and you can end a mission by hitting [ESC]. 

God Mode
Drop to the console during the game with the ` key and type: 

srv_hero 1 

Unknown Effect
Drop to the console during the game with the ` key and type: 

srv_light 1