Believe:

[g-mark]

If something is untrue, is it a belief? Even though we 'believe' it is true?

If something isn't true, then I would hold that it is non-belief, not a negative belief.

Can you explain please teacher. Because you stated:

belief - any cognitive content held as true
source: http://wordnetweb.princeton.edu/perl/webwn?s=belief

If we take the above definition as true, then every single thing that we understand and recognize as true, is counted as a belief. So everyone is a believer in something, but being a believer does not mean you have faith.

Or is this just your opinion. Who is to say your opinion is correct?

It's not an opinion, I am quoting the dictionary. Read the definition - belief - any cognitive content held as true. If you want to dispute the truth of the dictionary, take it up with them. I am merely using it because you asked.

And the definition of cognitive content is - the sum or range of what has been perceived, discovered, or learned

If we accept the above definitions, then anything that has been perceived, discovered, or learned is a belief, which means that anything we hold as true is a belief. As for what is not true, the correct way to describe it would be non-belief.

Ok thank you. Your definitions are good. I think I needed that. My strong suit wasn't grammer, more maths and science.

This is true when talking in terms of nouns. Very interesting actually.

With regards to faith: I found this.

be⋅lief
   /bɪˈlif/ Show Spelled Pronunciation [bi-leef] Show IPA
–noun
1. something believed; an opinion or conviction: a belief that the earth is flat.
2. confidence in the truth or existence of something not immediately susceptible to rigorous proof: a statement unworthy of belief.
3. confidence; faith; trust: a child's belief in his parents.
4. a religious tenet or tenets; religious creed or faith: the Christian belief.
Origin:
1125–75; earlier bile(e)ve (n. use of v.); r. ME bileave, equiv. to bi- be- + leave; cf. OE gelēafa (c. D geloof, G Glaube; akin to Goth galaubeins)

What do you think of point 3?