One of Lincoln's opinions is that America is a nation founded the idea that all men are created equal. Even though this is in the Declaration of Independence, it can be argued that this is not true since America has slavery.
Another opinion by Lincoln in this speech is that the world will not remember what is said at Gettysburg. This ends up being untrue, as this is one of the most studied speeches in American history.
Lastly, Lincoln believes that the government by the people will continue on. This statement at the time is supported by the fact that the Union is doing everything they can to preserve the nation.