The art of acting serves several purposes, but perhaps the most relevant is in providing an audience the opportunity to study an issue, theme or question in a focused, limited time-frame, with the skills of an author and actors employed to illuminate a particular area of interest. Acting also allows audience members to share the experience with others.
An actor can offer the joy of pure entertainment or offer escapism from reality. Comedy may be employed to lift the spirits of an audience (while comedy can also serve to illuminate serious social issues). Aristotle considered actors in ancient Greek theater as serving the vital role of allowing audiences to purge themselves of powerful emotions such as grief and terror, and to experience pity for tragic figures of Greek theater, such as Sophocles' tragic hero Oedipus in 'Oedipus Rex'.
Actors can also illuminate myriad issues that occur in contemporary life, and allow the theater experience to bring meaning to events that may lack coherence or meaning when experienced day-to-day. Actors can tackle roles that are overtly political, are historical in sweep, or those that are quite mundane, or intimate and personal.
Quality acting can serve as many functions as there are human experiences.