BN's English Usage Editorial
My peeve of the day is the passive tense. Consider the following two sentences from history (as far as we know, Cambodia is fine and unbombed today):
"Yesterday, Cambodia was bombed."
"Yesterday, U.S. planes bombed Cambodia."
Do these sentences mean the same thing? Either way Cambodia woke up one day in 1970 having been bombed. Does the distinction matter?
You bet it does.
The difference is the subject: the "who" of the action. To be complete, every sentence in English must have a subject and verb. He, she, it, you, we, or they "verb." The entity that gets "verbed" is the object. In the passive tense, the object still gets "verbed," but  the subject is not identified; the subject hides behind the passive verb.
In sentence one, Cambodia still gets royally verbed, but in sentence two, Prince Sihanouk finds out whom to blame for his country's verbing. The world asks questions, and the U.S. has to answer. The outcome changes.
Obviously, not all active/passive tense situations will be as important to world peace as our Cambodian example. Nonetheless, good writers use the active tense unless they actually mean to put a verb in the passive tense in order to make a point (or to shelter a subject). Good writing is intentional.
Using the active tense will make your writing more lively and interesting and will make you think about what you want to say (about whom) in every single sentence.