Press tilde (~) to open the console. Entering the codes without a number will show you their current value. When in noclip mode, you may raise or lower your character with the "Home" and "End" keys.

Effect	Code
god 0	Disable God mode.
god 1	Enable God mode.
noclip 0	Disable noclip.
noclip 1	Enable noclip.
speed #	Set movement speed.