Consider these 2 sentences:
1) John was told by the police to hand over the ipad.
2) The police told John to hand over the ipad.
Which of the two sentences gives you a faster comprehension of the idea, the scene and what's going on?
Hopefully you can tell it's the second one.
The first sentence is passive. It's passive because of the way the information is ordered. Specifically the order of the subjects and the action.
Who are the subjects?
The police and John
What is the action?
The police telling John to hand over the ipad.
In a passive sentence, the focus is on the subject that's being acted on, in this case it's John.
Whereas active sentence focuses on the subject that is acting, in this case the police.
The visual image forms more quickly with the active sentence as you can imagine someone doing that action.
While in a passive sentence, you're waiting on a second piece of information to complete the puzzle. This slight delay is enough to disrupt the comprehension for the reader. As a result the picture you're trying to create forms more slowly than if it's phrased actively.
The goal is to create a visual for the reader as quickly and as effortlessly as possible.