This second letter is addressed to “the dear lady and her children”. It is not clear who exactly this was; whether this was a specific lady or a figurative address to a church group. The Church being referred to as a lady reflecting the Church being the Bride of Christ. John again reminds them of the key command to “love one another” and to walk in obedience to God’s commands.
In the early days of the Church, there were many traveling evangelists and teachers as well as those we know as the Apostles. When they arrived in each place the believers there would care for them in their homes for the duration of their stay and then give them provisions as they moved on.
This appears to work well, except that there were those who were not preaching the Gospel, false teachers, who were taking advantage of the generosity of the believers. Some were therefore being deceived by this false teaching. The main purpose of this short letter is to alert the reader to be on their guard about welcoming these people into their homes and therefore unwittingly allowing the propagation of false teaching.
Many deceivers have gone out all over the world, people who do not acknowledge that Jesus Christ came as a human being. Such a person is a deceiver and the enemy of Chris. Be on your guard then so that you will not lose what we have worked for, but will receive your reward in full. (v 7&8)
John continues to remind them that the only true teaching is that of Christ. That anyone who does not teach this or tries to teach something else, or some “new revalation” is not of God. Therefore if anyone comes who does not bring the teaching of Christ; they should not welcome them into their homes.
Now most of the church of that time would meet in people’s homes, so this of course does not mean that they should not welcome anyone who was not part of the known fellowship of believers into their homes. (how would and unbeliever be able to hear the truth otherwise?) There are several instances mentioned throughout the New Testament where the Apostles and Elders would send a letter of introduction along with someone so that the recipients would know that they are trustworthy and sound and could welcome them fully.
They would therefore need to exercise caution with any traveling teachers who do not come with this recommendation. They could unwittingly allow false teaching which would lead people away from what they already knew.
I think it would be good to remember the Bereans again who were commended in Acts 17 v 10-11 for their diligent study of the Scriptures and testing that what was being taught was true. Now they did this with Paul and Silas, so we should definitely be checking out what we hear from the pulpit ourselves.
Quotes from The Good News Bible