As a professional who has been teaching others to write business correspondence for the past ten years, I feel more confident signing off letters or memos that are made up of sentences written in the active voice. Sentences written in the active voice are far more helpful in helping readers to visualize what the writer is trying to say; hence, they promote faster understanding.

Using sentences written in the passive voice gives me a feeling that what I signed off is something I cannot stand by, assert for, and at worst, fight for.

Food is something to eat. or
Food is something to be eaten.

Thanks

Usually, with a little thinking, most sentences can be converted from passive to active. In the above example, “Further research needs to be done to prove this hypothesis,” could be worded as “Future research will confirm or reject this hypothesis,” or “This hypothesis needs further examination.” “This hypothesis will be proved through future research.” (Note: no self-respecting scientist would write the original sentence since hypothesis are not “proved” nor can a person claim that a hypothesis will be proved.)