Our country is divided about immigration policies, the scope and limits of pluralism, the nature of religious liberty, and the extent of tolerance and diversity. These issues are not new to public debate and, in fact, date to the roots of American freedom more than three centuries ago. It may be helpful to revisit that story to glean insights for our time.

Monday  (July 30) marks the 300th anniversary of the death of William Penn, Pennsylvania's founder. The gentleman Quaker, political theorist, and real-estate developer was 73 when he died. An Oxford-educated Anglican turned religious dissident, he gained notoriety in his mid-20s for challenging the English Church-State establishment. His radically liberal idea was that the human conscience is free and people should be allowed to worship and live in ways that accord with their personal religious beliefs as informed by the Bible. In other words, compulsory worship and belief is not true faith. As Penn argued in his Great Case for Liberty of Conscience, "God only, and no other besides himself has endowed us with those excellent gifts of understanding, reason, judgment and faith…."

Penn's idea garnered a following in England, especially among the Society of Friends, or Quakers, and other marginalized religious sects. But his initial efforts to reform English law were not realized, at least in the mother country. The New World, however, offered the chance to model his political theory that faith and liberty could be successfully paired. Cashing in on a debt the Crown owed his late, war-hero father, Penn was granted a charter for a new colony with the caveat that it be named in honor of the elder Admiral Sir William Penn. This was an embarrassment to the Quaker son whose self-effacing humility eschewed personal aggrandizement as a vice. The 17th-century real-estate developer-politician had no interest in self-branding.

By the time Penn turned 36, he was the sole owner and proprietor of what we know as Pennsylvania, and he launched what he called "a holy experiment." Penn believed the virtue of love was central to life, including political life: "Love is above all; and when it prevails in us all, we shall all be lovely, and in love with God and one with another." The foundation of Pennsylvania's freedom was an ethic of love – liberty constrained by compassionate care for others and the common good. He named the capital city Philadelphia – a biblical word meaning "brotherly love."

A model of democratic liberalism, Pennsylvania became arguably the freest government in the world. Penn's 1701 constitution – the Charter of Privileges – irrevocably established liberty of conscience and religious freedom for the inhabitants, attracting universal attention for those longing for liberty. Immigrants flocked to Pennsylvania from not only the British Isles, but the rest of Europe.

One of them was a German religious dissident named Francis Daniel Pastorious, who sailed to Pennsylvania with 80 others. His shipboard passage described the diversity onboard: "There was a doctor of medicine with his wife and eight children, a French captain, a Dutch cake baker, an apothecary, a glassblower, a mason, a smith, a wheelwright, a cabinet maker, a cooper, a hat maker, a cobbler, a tailor, a gardener, farmers, seamstresses, etc. They were not only different in respect to age… and in respect to their occupations … but were also of such different religions and behaviors that I might not unfittingly compare the ship that bore them hither with Noah's Ark… ."

This is Pennsylvania's heritage of faith and liberty – a metaphorical Noah's Ark, where people could flee the diluvian judgment of European tyranny for the seedbed of political and economic prosperity. Though one of the newest colonies in America, Pennsylvania became the most religiously diverse, tolerant, cosmopolitan, and economically prosperous of British colonies. As Penn had hoped, it became the "seed of nation."

Is Penn's achievement cherished today? Does his vision of love still have relevance as America grapples with modern immigration policies, exploding pluralism, and expanding social diversity? And what about that fundamental and irrevocable right of religious liberty? Can Americans live together in harmony, even with our deepest differences? Is Penn's achievement in pairing faith and liberty still relevant?

Alan R. Crippen II is chief of exhibits and programs at the Faith and Liberty Discovery Center coming to Philadelphia's Independence Mall in 2020.