One of the things that never scares me as a Dungeon Master is whether or not I’ll be able to challenge my players.
A lot of people worry about this. As a DM you don’t want the game to be too easy and of no consequence. You also don’t want it to be an adversarial and impossible grind that punishes player characters just for existing. You need to find just the right balance of challenge.
I’ve got lots of little tricks that I’ve learned along the way, but the one that has been the most freeing for me has been this little rule: “Your character only stays dead if you want them to.”
I unabashedly embrace resurrection in my games. I always provide a way back from the dead, and one that doesn’t take up too much table time, though it might provide an opportunity for other characters to make a sacrifice for their fallen ally. In a current campaign one player made a deal with an evil NPC to raise their comrade from the dead, while another had an opportunity to offer up one of their own bones for the sake of a resurrection.
Embracing resurrection in your TTRPG also teaches an important faith lesson: Death is not the end of our story. God overcame death, so that we could do the same. Death need not be feared.
Without being afraid of killing the PCs at my table, I embrace things like putting monsters in front of players that hit like a dump truck and knock them out, rolling dice in the open and letting them fall where they lie, putting giant mobs of monsters in front of them, making them figure out how to actually overcome difficult challenges or even come back from the dead.
I’ve knocked out and killed plenty of characters in my games, but there’s always that rule “Your character only stays dead if you want them to.” This rule has created deep and meaningful story moments as the players get the opportunity to role play with grief and loss, emotions that we often shun. It’s beneficial for us to experience these grittier emotions, especially if we can do so in a relatively safe way. A bit of grit is a good thing. The grit gives our stories and our lives definition.
Character death also has a game mechanics benefit. It gives players an opportunity to respec their PCs, or say goodbye and build a whole new character if they like. I find that a lot of times they’re ready for some kind of change. It’s an opportunity for the player to consider their character and if their story is complete just yet.
And if you TPK the party of heroes? Well it’s the same rule. They stay dead only if the players want them to. Mostly a TPK is just an opportunity to up the stakes a bit. Fail forward and raise them up in a hairy situation with an opportunity to overcome defeat.

You can’t learn to rise if you never get the chance to fall.