Make Page Display Categories instead

Here is the page:

https://habitswap.com/?page_id=178

Right now, it displays ALL of the posts. However, I want to modify the code in this page so it displays content from only 1 category. This is the code of the page template for the page above:

[Large code excerpt removed by moderator per forum rules. Please use the pastebin for all large code excerpts. It works better anyway.]

Please tell me what to modify in the code above so it only displays one category in the page.

Thanks,

Chris