Yes, punctuation can make a huge difference in the meaning of even the most simple sentences. Two examples that stress the importance of a comma immediately spring to mind, with the first example being the classic, "I'm hungry! Let's eat Grandma." The better-punctuated sentence would read, "I'm hungry! Let's eat, Grandma." The second example demonstrating the importance of a comma is, "I helped my uncle Jack off a horse," and the more commonly-needed sentence being, "I helped my uncle, Jack, off a horse."