С одной надежды не сшить одежды

If you rely on hope only but do not work or act, you will gain noth ing. See Одной надеждой не проживешь (O)

Cf: Не that lives upon hope will die fasting (Am.). Hope is a good breakfast, but a bad supper (Br.). Hope is a good breakfast, but it is a bad supper (Am.). Hope is a slender reed for a stout man to lean on (Am.). Hope is the poor man's bread (Am.)