As fast-traveling is undoubtedly very handy in a game that uses Metroidvania-style exploration, here's how to unlock Valor Mortis' fast travel system.
How to use fast travel in Valor Mortis
Don't worry; Valor Mortis does have a fast travel system. However, it'll take a few hours of playtime to unlock it, as you must reach the Abandoned Church for the first time. The Abandoned Church acts as a home base where you can speak with other survivors, upgrade weapons, and purchase items.
You will reach the Abandoned Church, and thus unlock fast travel, at the start of Chapter 3: Rendezvous. This means that, from Chapter 3 onward, it's much easier to travel to previous areas and unlock new pathways. Chapter 3 will begin once you've defeated General Lothaire.
Fast-traveling in Valor Mortis is quite simple; rest at any lantern, choose "travel," and select your destination. Just keep in mind that resting revives every enemy in the game except bosses.