Heresy
Conclusion
The Lollards and the Hussites were by no means the only heretical movements of the 14th and 15th centuries. As stated in the opening, there were plenty of heresies in part because the Church was being more and more precise about what constituted heresy, and was getting better organized and so better able to prosecute heresy. Also, the many calls for reform of the Church routinely included calls to eradicate heresy.
Besides outright heresy, there were plenty of movements that caused difficulties for the Church, were openly critical, or departed from "standard" practice in one way or another that the Church was either unwilling or unable to classify as heresy. Among these were the various movements of "lay piety" in which laymen took upon themselves their own spiritual welfare. They met to pray together, to read the Bible, or to discuss points of doctrine and practice. They met, too, to enjoy Christian fellowship with others who shared their idea of a good Christian life. Once in a while this or that individual or even a group might be declared heretical, but by and large these went their own way in the late Middle Ages.
What all these movements, heretical or otherwise, indicate is that spirituality was alive and well in late medieval society. There's no hint of secularization or a falling away from religion, or even of a criticism of religion unless it be that society should be more religious. The "paganism" we see in Renaissance art was not an indicator of the spiritual temperment of the times, but was merely an artistic convention. Religion mattered a great deal, at every level of society, as would be borne out in action and in blood over the following centuries.