I'll give you a quick definition of each of these:

• voice:  a vague term that is used to describe the specific features of a written work and how its told; the characteristics displayed by the narrator or speaker: usually analyzed in terms of tone, style, or personality.  Not to be confused with point-if-view.
• mood:  the emotional aura invoked by a work, synonymous with atmosphere.
• tone:  the speaker's attitude toward his/her subject.
• theme:  an abstract idea that emerges from a work; the ideas revealed by a work.  Not to be confused with one-livers that tell a reader how to live.