I came across this illuminating quote on English Puritanism in the biographical introduction to John Flavel's The Mystery of Providence.
The history of Puritanism is quite remarkable. As a movement for thorough reform of the Church on the basis of the Word of God, it was indeed as old as the Reformation. But if the Reformation revived preaching, the Puritans came to stand for preaching of a particular kind. It has been the verdict of competent judges ever since that, for applying the Word of God to the conscience with power, thoroughness and unction, the Puritans stand alone. Yet it is difficult to define in detail how they differ from preachers of other ages. It is as difficult to explain how the movement arose, in a short time producing a host of outstanding preachers, and then, a hundred years or so later, how this supply dried up. If we take the view that the Puritan movement was nothing less than an outpouring of the Holy Spirit upon the Church in England, then it is a signal instance of the principle of divine working enunciated by our Lord: 'The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth. . . .'
This writer notes that John Flavel was one of the few Puritan leaders still in ministry at the time of the 1688 Glorious Revolution. The overthrow of James II and ascension to power of William and Mary meant that England would never be Roman Catholic. Yet, this decisive victory for Protestantism in England wasn't a victory for the Puritans. In fact, in the wake of the Great Ejection of 1662 which saw non-conformist pastors expelled from the national church, the principles of total reformation advocated by the Puritans had been largely defeated. The high church Anglicanism they saw as only partial reformation had carried the day.
One could look back and say that the Puritan movement was a failure. On the other hand, which English-speaking Christians of that period are still being read today? Who was it that profoundly influenced George Whitefield and the Wesley brothers, helping to spark the great revivals of the 18th century? Answer: it was Puritans like John Flavel, John Owen, Thomas Watson, and many others, who continue to provide a model of robust Calvinistic doctrine and deep piety. Rightly have they been compared to the giant Redwood trees of California.
"As Redwoods attract the eye, because they overtop other trees, so the mature holiness and fortitude of the great Puritans shine before us as a kind of beacon light, overtopping the stature of the majority of Christians in most eras, and certainly so in this age of crushing urban collectivism, when Western Christians sometimes feel and often look like ants on an anthill and puppets on a string. In this situation the teaching and example of the Puritans has much to say to us." (J.I. Packer)