From the beginnings of the Church of God in the 1st Century AD, there has been a consistent problem with false teachers. Although the specific false doctrines that leaders of the Church of God have been most focused on has changed from time to time depending on the heresy de jour, there has been a consistent concern with the heresies that were entering into the Church of God through the patronage of various false preachers. Indeed, this concern goes back well into the biblical period, as it forms a large part of Paul’s lament to the elders (or presbyters) of the Church of God in Ephesus in Acts 20:28-31: “Therefore take heed to yourselves and to all the flock, among which the Holy Spirit has made you overseers, to shepherd the church of God which He purchased with His own blood. For I know this, that after my departure savage wolves will come in among you, not sparing the flock. Also from among yourselves men will rise up, speaking perverse things, to draw away the disciples after themselves. Therefore watch, and remember that for three years I did not cease to warn everyone night and day with tears.” Let us note here that there are two sources of trouble identified by Paul: the first is false ministers coming from outside and causing chaos and confusion by deceiving the brethren, and the second is false ministers rising up from among the brethren themselves seeking a following through novel (false) doctrines that promote themselves as some sort of biblical expert despite not having been appointed to such an office by God.
Such concerns about being good shepherds are not found only in the writings of Paul. While we have been a bit hard on the Didache previously  concerning some of its approaches to matters spoken of in scripture, it is worthwhile to point out that in its concern for standing firm against false prophets that the Didache closely resembles 2 John. Since these documents are both fairly brief in the way that they deal with the problem of false leaders and strikingly similar in their language, it is worth looking at them as part of a late first and early second century context. Given that we have already seen a striking (if unexpected) connection between the Didache and 3 John, the fact that there is a similar if more praiseworthy connection between the Didache and 2 John helps place it further in the context of being a work of about the same time as those epistles.
First, let us look at what 2 John :7-11 says about false leaders: “For many deceivers have gone out into the world who do not confess Jesus Christ as coming in the flesh. This is a deceiver and an antichrist. Look to yourselves, that we do not lose those things we worked for, but that we may receive a full reward. Whoever transgresses and does not abide in the doctrine of Christ does not have God. He who abides in the doctrine of Christ has both the Father and the Son. If anyone comes to you and does not bring this doctrine, do not receive him into your house nor greet him; for he who greets him shares in his evil deeds.” This is a fiercely worded but unambiguous position that if we encounter people who promote a false Gospel that we are not to show hospitality to them or provide them with material support because to be friendly and supportive of evil is to share in that evil even if we are not promoting it ourselves. This is a straightforwardly serious message that is clearly applicable in our own times to those who would seek to have their own ministries with doctrines not in accordance with scripture who continually seek the support of other people by buying their books and speaking highly of them and their novel (false) interpretations of scripture by which they seek to be viewed as important people among professed Christians.
In the Didache, in the first part of section 11, we see a similar statement to the above discussion by John about false teachers: “If anyone comes and instructs you on the foregoing lines, make him welcome. But should the instructor himself then turn round and introduce teaching of a different and subversive nature, pay no attention to him. If it aims at promoting righteousness and knowledge of the Lord, though, welcome him as you would the Lord (195).” Here again we see a strong concern of the ministry for teachings that are subversive. To be sure, there are some authorities that are corrupt in this present evil world that are worthy of subversion, but this is a hazardous task that is not to be undertaken lightly or without an acceptance of the risks that one is running by so doing. It can be said in general, though, that there is a universal hostility to subversion by all who are in positions of authority, whether or not these are godly and righteous authorities. The whole appeal of having offices of authority of any kind is to receive the respect and honor of others and to put into practice and to enforce one’s worldviews and one’s perspective on others.
It is therefore little wonder that there is a striking similarity between the command of John for believers to disregard those ministers who bring a different doctrine and the similar statements found in the Didache. Indeed, there has likely never been a single conscientious minister at any place or time within the entire history of the Church of God from the first century to today, as long as this world may last until the return of Jesus Christ, for whom this is not an issue. To be sure, the false doctrines may change. During the time of John, for example, there was a concern with docetism, the belief that Jesus Christ did not come in the flesh but only appeared to come and possessed some poor schmuck before abandoning him in articulo mortis, at the moment of death. During our time there are many false Gospels that are popular, ranging from some false Gospels that view the human traditions of the Jews as being something that Christians should follow (what could politely be termed as Judaizing tendencies) to other positions that are extremely popular by which the laws and ways of God the Father and Jesus Christ are attacked as judaizing because of lingering anti-Semitic hostility to the Sabbath and Holy Days and related doctrines that, as we have noted elsewhere, have been the subject of ferocious contention among those who claimed to follow Jesus Christ almost from the very beginning.
Some things never change when it comes to doctrinal struggles, and the struggle of leaders of the Church of God against false doctrines was present from the beginning of the Church until this day, and will continue as long as there are human believers in a world full of error and false interpretations as well as people who want to use what appear to be novel interpretations or the shiny baubles of false doctrines to attract a following for themselves. It is not surprising at all, therefore, that wherever we find a manual of church conduct or people whose concerns are with teaching or enforcing standards of congregational discipline that the concern for false preachers and leaders should be at the forefront in their minds. That we can find such matters mentioned several times in scripture as well as in the writings of nonscriptural but still ancient works reminds us that the struggles faced by leaders in defending the truth from error has been an ceaseless struggle from the very beginnings of Christianity to this day.
 See, for example: