Contrasting language is usually a wee bit difficult to parse. For example, when someone says that they love you and hate you in the same breath, they're usually a) Gnash b) in a soap opera or c) intentionally trying to be confusing.

But the Gettysburg Address was filled with contrasting language that effectively strengthened Lincoln's words…because that Honest Abe could do just about anything.

Check out this line:

[…] those who here gave their lives that that nation might live. (4)

Dang. That's pretty powerful stuff.

This one line both paid tribute to the brave Union soldiers and painted their sacrifice as not just another battlefield statistic but as necessary for the very survival of the United States. The contrast between the death of the soldiers and the life of the nation must have been excruciatingly obvious against the bloodied battlefield background where the speech took place.