One common definition is:
“Freemasonry is a system of morality, veiled in allegory, and illustrated by symbols.”
Most Worshipful Brother Benjamin Franklin, one of the earliest American Masons, offers further explanation…
Video courtesy of the Maryland Freemasons YouTube channel
But it’s so much more than that…
Freemasonry is a broad system of Morals and Ethics. That is, a science of human duties, whose principals are accepted by all religions as essential to human excellence. The cornerstone of these principles rests upon the recognition of a Divine Truth that mankind has a common origin and a common destiny; and that God is the Creator and Father of all of us. Out of that relationship with Deity grows the Brotherhood of Man. Freemasonry’s great purpose is to intensify that relationship. Thus, Freemasonry teaches Love, Faith, and Duty, unites man in the strong embrace of fraternal fellowship, and induces emulation of who can best work and best agree. Freemasonry thus becomes a system of spiritual education wherein is taught not only the virtues, but also the useful lessons of everyday life.
– Most Worshipful Brother Jeffrey O. Nations, P.G.M. of Masons in Missouri and R.W.B. Phillip G. Elam, Past Grand Orator of Masons in Missouri
Whatever formalities we may have gone through in connection with our admission into the Order, we cannot be said to have been “regularly initiated” into Masonry so long as we regard the Craft as merely an incident of social life and treat its ceremonies as but rites of an archaic and perfunctory nature. The Craft, as I have already suggested, was given out to the world, from more secret sources still, as a great experiment and means of grace, and as a great opportunity for those who cared to avail themselves of what is little known and little taught outside certain sanctuaries of concealment. It was intended to furnish forth an epitome or synopsis, in dramatic form, of the spiritual regeneration of man; and to throw out hints and suggestions that might lead those capable of discerning its deeper purpose and symbolism into still deeper initiations than the merely superficial ones enacted in our Lodges.
– Worshipful Brother W.L. Wilmshurst, “The Meaning of FreeMasonry”