That information is unnecessary.

That information is completely unnecessary.

He thinks that war is a necessary evil.

He doesn't need to unnecessarily take on a fight.

He decided to buy a new car on credit.

Because an earthquake forecast was issued, I stocked up on food.

It is important to stock up on food before an earthquake.

He bought all the new comics in bulk, like an adult.

He bought all the new comics in bulk.

He bought too much on credit, and his debt increased.