In verse 10 John sets out one practical application of how to defend the truth: If anyone comes to you and does not bring this teaching, do not receive him into your house. Hospitality for traveling teachers was common in the culture (cf. Luke 9:1-6; 10:1-12). The prohibition here is not to turn away the ignorant; it does not mean that believers may not invite unbelieverseven those who belong to a cult or false religioninto their midst. That would make giving the truth to them difficult, if not impossible. The point is that believers are not to welcome and provide care for traveling false teachers, who seek to stay in their homes, thereby giving the appearance of affirming what they teach and lending them credibility
Johns use of the conjunction ei (if) with an indicative verb indicates a condition that is likely true. Apparently, the lady to whom he wrote had for whatever reason, in the name of Christian fellowship, already welcomed false teachers into her home. It was just such compassionate, well-meaning people that the false teachers sought out (cf. 2 Tim. 3:6); since churches were supposed to be protected by elders who were skilled teachers of the Word (1 Tim. 3:2; Titus 1:9), they should have been less susceptible to the lies propagated by the deceivers. Having established themselves in homes, the false teachers hoped eventually to worm their way into the churches. It is much the same today, as false teaching insidiously invades Christian homes through television, radio, the Internet, and literature.
So threatening are these emissaries of Satan that Jo[h]n went on to forbid even giving them a greeting; for the one who gives him a greeting participates in his evil deeds. Irenaeus relates that the church father Polycarp, when asked by the notorious heretic Marcion, Do you know me? replied, I do know youthe firstborn of Satan (Against Heresies, 3.3.4). John himself once encountered Cerinthus (another notorious heretic) in a public bathhouse in Ephesus. Instead of greeting him, however, John turned and fled, exclaiming to those with him, Let us fly, lest even the bath-house fall down, because Cerinthus, the enemy of the truth, is within (Irenaeus, Against Heresies, 3.3.4).
A cult is a religious group (but do not have to be religious) that follows a particular theological system. From the view of Christianity a cult distorts the doctrines that affect salvation sufficiently to cause it to be unattainable. For example, it is an essential doctrine of Christianity that there is only one God (Isaiah 43:10; 44:6; 44:8; 45:5) and that believing in a false God brings judgment (Exodus 20:1-6). If a group were to affirm that there is more than one God (i.e., Mormonism), then it would violate an essential doctrine and be outside the Christian faith. Another essential would be that Jesus is God in flesh (John 1:1,14; Col. 2:9) and that to deny it means a person will die in his sins, John 8:24. The Jehovah's Witnesses deny Christ's deity and are, therefore, not Christian.
From the view of Christianity a cult distorts the doctrines that affect salvation sufficiently to cause it to be unattainable.
Well without casting stones, the problem is that there's no consensus among the various mainstream Christian denominations as to what those doctrines are. Whenever you start discussing the differences between denominations, the battle lines are quickly drawn as to whose details are "true" and whose are heresy or apostasy.
Well without casting stones, the problem is that there's no consensus among the various mainstream Christian denominations as to what those doctrines are.
Sure there are Willie. I just gave you the Scriptural principles held by all Christians. If they don't meet the criteria stated and claim they are Christian then that group is a cult.
Now different denominations may claim others are in error, but won't kick them out the door or deny fellowship.
Well without casting stones, the problem is that there's no consensus among the various mainstream Christian denominations as to what those doctrines are. Whenever you start discussing the differences between denominations, the battle lines are quickly drawn as to whose details are "true" and whose are heresy or apostasy.
A cult teaches false doctrine regarding the person of Christ.