Charity provides crumbs from the table; justice offers a place at the table.
But there is nothing idealized or romantic about the difference between a society whose arrangements roughly serve all its citizens (something otherwise known as social justice) and one whose institutions have been converted into a stupendous fraud. That can be the difference between democracy and plutocracy.
Charity depends on the vicissitudes of whim and personal wealth; justice depends on commitment instead of circumstance. Faith-based charity provides crumbs from the table; faith-based justice offers a place at the table.