What is the meaning of [The truth shall set you free, or The truth will set you free]

“Sustained by truth, man becomes a most sublime spectacle. Here is the foundation of all true eloquence and dignity – the conscience untrammeled gives boldness and majesty, and the whole soul rises to the glorious height of its own nobility.”, Porter, William Henry (1845). Proverbs, Arranged in Alphabetical Order …. Munroe and Company. p. 194.