Jason ate the cookie.
The cookie was eaten by Jason.
Which sentence above do you find more interesting to read? Did one of them provide a better picture in your head of what was going on? Both sentences tell us about Jason eating a cookie, but the first one was more clear and you can easily visualize the action.
The first sentence is Active Voice. The second sentence was Passive. Active voice makes for more interesting reading and is likely to keep your reader interested. The readers will find themselves caring more about your character as well because it would be as if they were actually there.
There’s a bonus to using Active Voice – it helps when you are revising and cutting words. If you take a look at the two sentences above again, you’ll notice the first sentence (Active Voice) has four words. The second (Passive Voice) sentence has six. Imagine cutting two or more words from many sentences in your manuscript. You may find it easier to meet your word count requirement, which can only improve your chances of publication.
Just as you write, it makes your writing more concise and IMHO, more conversational.