Create a File called "Ar.cfg"
Copy the following and save it.

ScreenWidth 800
ScreenHeight 600
RunWorld worlds\intro.w
StartMenu 1
loadmodels 1
drawfps 1
drawsky 1
numconsolelines 0
DrawCharacterPaths 0
consolelog 0
RaportTextures 0
RaportSubsets 0
god 1
DebugCharacters 0
RaportVariables 0
DrawDisplace 0
debug 0
RaportTechs 0

Replace "Ar.cfg" with new one for god mode. 

Note: You may have to reconfigure some graphic options.