We all start small. We pray and pick up what mitzvot we can practice. We respect each other and do right by others. We strive to learn what G-d wants from us through Torah study - and suddenly we are all part of the foundation on which the world is built.
Source: SoB's Take on Pirke Avot - Bits and Bobs - http://groups.gaia.com/torah/discussions/view/399693#406657