UPDATE 1:

iddqd
Activates God Mode but not including hazards: On Nightmare Difficulty, causes health meter to tick down.
idkfa
Activates fully upgraded Health, Armor, Ammo Capacity. Also, all Weapons, Weapon Mods fully upgraded, Suit Mods, and all Suit Mod slots.
idfa
Activates fully upgraded Health, Armor, and Ammo Capacity.
idka
Activates all Weapons and Weapon Mods. All Weapon Mods are fully upgraded.
ida
Activates all Suit Mods and full Suit Mod slots.
iddt
Unlocks all secrets, items, and unexplored area of the map.
idgk
Activates enemy immunity to normal weapons. Demons can only be defeated with Glory Kills.

UPDATE 2:

Here are some DOOM Console Commands from the previous DOOM game that may or may not work in this reboot:

• IDDQD on/off invincibility
• IDFA weapons and ammunition
• IDKFA ammo, keys and weapons
• IDCLIP on/off passing through walls (Doom II/ Final Doom)
• IDSPISPOPD enable passing through walls for DOOM 1
• IDCHOPPERS to get the chainsaw and the encrypted message
• When the IDDT Automap mode allows you to switch modes: normal map, completely open map, open map with objects and enemies
• IDBEHOLD to berserker pack
• IDBEHOLDV gain temporary invulnerability
• IDBEHOLDI gain temporary invisibility
• IDBEHOLDA automatically maps
• IDBEHOLDR to obtain anti-radiation suit
• IDBEHOLDL get light-amplification visor - night vision
• IDCLEVxy teleporting to level y (1-9) episode x (1-3) for Doom, (x=1 to 32 for Doom II)
• IDMYPOS shows the coordinates and direction of movement
• IDMUSx the change of music x - music level (Doom II/ Final Doom)

UPDATE 3 (Codes Confirmed To Be Working):

• God Mode: cvarAdd g_permaGodMode 1 (or just type: god)
• Infinite Ammo: cvarAdd g_permaInfiniteAmmo 1
• Dumb AI: cvarAdd g_inhibitAi 1
• Unlock Perks: DebugUnlockPerkByAbility -1
• Unlock Perks 2: DebugUnlockPerkByRequirement -1
• Draw FPS: Com_showFPS 3
• Change FOV: g_fov X – where X is the FOV number