Portal

Portals are doorways that lead to different dimensions or simply shortcuts on Earth. They can be opened by drawing the correct sequence of symbols on any surface. The accuracy varies in between portals, depending on the level of detail done upon drawing. If the coordinates are not specified, the portal leads to a random point within the general area.

Angels can travel without the use of portals, but it's easier to use a direct portal if you know the "address".

Enoch opens a portal to Hell in episode 3. Unable to draw a detailed portal, he ends up in an unknown part of Hell.

Satan opens a portal to the gates of Heaven in episode 4. He tells Yohana and Mamre to hold their breath as they go through.

A seraph guards a permanent portal in episode 5. It leads to God's throne room.