Statements (or propositions) are things that describe the world as being a certain way.

For example: 'The earth is flat' is a statement.  So is 'the earth is round'.

Truth is a property that a statement can have.  The true statements have it; the false one's don't.

An analysis of truth: a statement is true if and only if the world really is the way the statement says the world is.

This analysis states exactly the conditions under which a statement is true.  Since it says nothing about what anyone knows or believes, we can see that truth is independent of what anyone thinks.  That is, truth is "objective."  A statement gets to be true not because everyone thinks it is true, but rather because it describes the way the world really is.

Here is an argument to prove that there are true statements that are not known to be true be anyone.

1. If 'the number of stars is even' is true, then there is a truth that no one knows.
2. If 'the number of stars is odd' is true, then there is a truth that no one knows.
3. Either 'the number of stars is even' is true or 'the number of stars is odd' is true.
4. Therefore, there is a truth that no one knows.

Premises 1 and 2 are true because no one knows how many stars there are.
Premise 3 is clearly true because it has to be either one or the other.  Either the number of stars is even or odd.
The conclusion (line 4) follows logically from the premises.