How can physicists say that particles, for example the photon or theoretical graviton, 'carry' forces? It just seems more logical to me that forces are caused by disturbances in a universal field that manifests itself as the Four Fundamental Forces. So a nucleon absorbs a gluon (Strong force) emited by another nucleon and they're automatically supposed to be attracted to eachother? Wouldn't it be more likely that forces are caused by fields themselves, not particles? Can anyone explain this to me?

Particles are just parts of a field in a similar sense as a wave (particle) is part of the ocean (field).

So they're like metaphors for the way fields work? Cool.

It´s rather a way to (mathematically) describe the exitation/state of a field than only a metaphor. You can describe the state of the ocean surface by giving a water-height to each point or you can start with a flat surface and add waves (areas where the height is raised) to it. The former method clearly describes the state but the latter might be more practically interesting for certain applications (e.g. a surfer).

While describing a field in QFT is slightly different technically, the idea to get a practical (i.e. useful) description of the field by using waves/particles is the same.