Resonance structures contribute to the stability of organic molecules by allowing the delocalization of electrons across different parts of the molecule. This delocalization leads to a lowering of potential energy, as the charge or electron-rich areas can be spread out over a larger volume of space. The concept of resonance averages these structures to envision a more stable, hybrid form of the molecule, where bond lengths and charges are often intermediate between those of the individual resonance forms. This stabilization is particularly significant in ions or molecules with conjugated π systems, such as benzene, contributing to increased stability and often reactivity.