Energy is not created or destroyed, it only gets transformed from one form to another. Fuel represents a storage of energy. So when you burn fuel, you are taking the energy contained in that fuel and using it to create heat energy, harness it to make a car move, generate electricity (which you seem to agree is energy as well), or whatever.

Think about high school physics. Bring a 200 pound weight to the top of a tower, and it has potential energy. Nothing happens, just as nothing happens to fuel without a spark, but if you drop it out turns into kinetic energy. Let it hit the ground, and the sidewalk will absorb some of that energy as it breaks, it gets absorbed into sound energy, the whole process repeats on a smaller scale as it bounces, etc. All energy, and not in the hippy “the universe is all energy, maaan” kind of way.

The first part of this Technology Connections video also shows how propane is stored energy that gets converted: https://youtu.be/OOK5xkFijPc - just because that spark was needed to convert the energy in that propane to heat, doesn’t mean the spark is the source of the energy. If you’re going to be pedantic enough that I have to explain that.