Prayer for All of Klal Yisroel

Rav Pinchos taught that a tefillah that is not said in the name of all of Klal Yisroel is not a tefillah. Most of the formal tefillos are not for ourselves alone but for all of us, and they are written in the plural, not the singular. We daven in a congregation to remind ourselves that we are not alone in our needs.