John Foxe in the introduction to the 1684 edition to Foxe's Book of Martyrs speaks to one of the core issues of reformation: persecution from within the church. It is the repugnance of those present in the church toward those who have a hand in reforming it. Foxe believed that there are always two groups within the visible church – the true church and the false. It is those of the false church, which are participants in it but have not really embraced the gospel who cause problems for those that have.
And many times, it happeneth, that as between the world and the kingdom of Christ there is a continual repungnance: so between these two parts of this visible church aforesaid oft times growth great Variance and mortal persecution, in so much that sometime the true church of Christ hath no greater enemies, than of their own profession and company, as happened not only in the time of Christ and his Apostles, but also from time to time almost continually, but especially in these later days of the church under the persecution of antichrist and his retinue, as by the reading of this volume more manifestly heareafter may appear.