These statements, now the commonly held beliefs of most Americans, were revolutionary in the late 1600s. They flow naturally from Penn's Quaker experience and beliefs.
"Governments, like clocks, go from the motions men give them, and as governments are made and moved by men, so by them are they ruined too. Wherefore governments rather depend upon men than men upon governments." (From preface to the Frame of Government of Pennsylvania, 1682)
"It is certain that the most natural and human government is that of consent, for that binds freely, ... when men hold their liberty by true obedience to rules of their own making." (Towards the Present and Future Peace of Europe, 1693)
"No people can be truly happy, though under the greatest enjoyments of civil liberties, if abridged of the Freedom of their Conscience as to their Religious Profession and Worship." (Pennsylvania Charter of Liberties, 1701)
"If we will not be governed by God, we must be governed by tyrants."
"Let the people think they Govern and they will be Govern'd. This cannot fail if Those they Trust, are Trusted." (From Some Fruits of Solitude)
"By Liberty of Conscience, we understand not only a mere Liberty of the Mind ... but the exercise of ourselves in a visible way of worship, upon our believing it to be indispensably required at our hands, that if we neglect it for fear or favor of any mortal man, we sin, and incur divine wrath." (Written in Newgate Prison, 1670)
"It is great Wisdom in Princes of both sorts, not to strain Points too high with their people. For whether the People have a Right to oppose them or not, they are ever sure to attempt it when things are carried too far; though the Remedy oftentimes proves worse than the disease." (from Some Fruits of Solitude)
"We meet on the broad pathway of good faith and good will; no advantage shall be taken on either side, but all shall be openness and love." (Addressed to the Leni-Lenape, 30 November 1682 at Shackamaxon)