Thanks to a wonderful plugin by Matt Read, you could fix this easily.

First, you’ll want to grab the plugin from his website and install it.

If you are unaware, that means unzipping and uploading the file into your BLOGROOT/wp-content/plugins/ directory.

How to Display all Posts on the Category Page in Wordpress

If this article helps you, then donate money to him, not me.

Head over to Options / CQS and you should be presented with this screen.

I dislike cluttered homepages.