The Barcelona forward was eager to heap praise on the efforts of his teammates during the tournament in Brazil, and he's confident Alejandro Sabella's side are fully prepared to face Germany on Sunday night.
"My dreams and my hopes are being fulfilled due to the hard work and sacrifice of a team that has given everything from match one," Messi wrote on his official Facebook page.
"We knew it was possible. Our people, the Argentinians, they have carried us here, but the dream is not over yet. We want to win and we are ready!
"We will play the most important match of our lives for our country."
Messi has top-scored for Argentina at the World Cup with four goals.