The first excerpt states that basically when one is suffering or in pain, that "Representatives of the United States of America, in General Congress, Assembled, appealing to the Supreme Judge of the world for the rectitude of our intentions, do, in the Name, and by Authority of the good People of these Colonies, solemnly publish and declare, That these United Colonies are, and of Right ought to be Free and Independent States" Meaning that the representatives will annihilate all links to any political connections and we shall be free.
The second excerpt states that in krder to "create a more perfect union" they will establish justice and defense and secure the safety of their citizens, similar to the first excerpt.
The two differ because the first excerpt is longer, and well informed, and has a variety of words and is highly detailed, while the second excerpt is shorter and less detailed. The tone of the two are ensuring and honest, as they both state that they want to free and protect the citizens.