The argument that Franklin D. Roosevelt is making is that all people deserve certain freedoms. He said people deserved to have freedoms of speech and expressions, freedom of worship, freedom from want, and freedom from fear. He wanted people to know that this was the reason that they were going to fight in World War ll. He was trying to tell the people that this was his vision, and this is what he wants for American. "In the future days, which we seek to make secure, we look forward to a world founded upon four essential freedoms."
I hope this helps!
~kaikers