yes you do.
Double quotation marks, or so called speech marks, can be used anytime you want to set off words or sentences as dialogue. Single quotes, italics, or bold can set off a single word or phase that is not dialogue but simply for 'emphasis'.
Italics are intended for sparingly use, only on a word or phrase. Therefore, you should not italicize a whole paragraph. The only time this may differ is if quoting a whole paragraph and if following certain style rules. You would highlight the entire paragraph, and click on the Italics button in MS Word.
Italics(:
Yes, you can use italics for emphasis in your writing.
Italics in brackets are often used to denote a change or emphasis added by the person quoting the text, rather than a part of the original quote. This helps distinguish the modifications made by the quoter from the original text.
It is more common in journalism to use italics for the title of a newspaper. This helps differentiate the title from the rest of the text and conforms to AP style guidelines.
Writers use italics to emphasize words or phrases, and sometimes to indicate thoughts.
Italics
No. Use italics or underline (I believe italics is the most current format).
Use Bold, Italics or underline it.
If you are simply presenting a list of The Commandments I wouldn't see the point in using italics, but if you are quoting a Commandment here and there throughout the argument, italics would probably read better than quotation marks; it would look smoother, and perhaps draw more attention to the particular line.
italics