Active voice makes it clear who is doing what. In an active sentence, the person that is acting is the subject. Passive sentences obscure or omit the sentence subject.

Use passive voice when the sentence object is more important than the subject. The active voice is generally easier to read.

Examples (subject, object)

Before: Our results will be discussed.
After: We will discuss our results.

Before: Wolverine was made to be a weapon.
After: The government made Wolverine. Wolverine is a weapon.