Humanists and the Reformation
Here is one line of thought:
The aim of the Humanists was to promote the unhampered intellectual development of man, who was able to perfect himself through the study of the ancients, the classical world, and by observation of the natural world. This was in opposition to the scholastics, and to the more conservative teachings of the catholic church, which promoted the infallibility of the pope, the inability of man to comprehend the works of God, etc.
Prior to, say, 1517, there were reformers within the Catholic church. Not only were there the radical reformers such as the Lollards and the Hussites but at the other end of the scale there were the so-called "renaissance popes" beginning with Nicholas V.
The problem is that by 1517 the scholastics had pretty much dried up and blown away. The superior intellectual development of the humanists had lead to humanism becoming the dominant movement throughout Europe.
Now most of the leading reformers and many (but not all) of the leading humanists left the Catholic church and went over to the Protestants -- Martin Luther et al. A case in point is one of the leading Humanists of the period -- Zwingli who lead the Swiss reformation.
The Scholasticism/Humanism divide didn't always flow over onto the Catholic/Reformed debate - Italy was pretty darn Humanist, and stayed pretty darn Catholic, and of course there were others such as the numero uno humanist of the day, Erasmus, who remained Catholic.
So the debate which had been raging for a hundred years or more changed in nature and character, but was essentially the same debate -- the thinking man vs the Catholic Church establishment, and may or may not have involved the same people on each side.
Of course there were real close links between the Gallician program of, say, either the court-centered Wyclif Knights or the pre-Humanist John of Paris (esp On Royal and Papal Power) and the program of Martin Luther.