It entirely depends on what type of php file it is! A file with a php suffix could either be a web page, or a php script file.
If it's a php script file, then you will never download it in a month of Sundays unless you have ftp access (you know, like passwords and username).
The reason is that php is a server side script. That means the php script files stay hidden away from snoopers and kept hidden by the server. The godaddy servers! Just one of the beautiful things to love about php.