How does 2 John Practically Apply to Christians Today?
Below I have listed the ways in which 2 John practically applies to Christians today.
1. Two groups are identified—a group noted as the children of the dear lady (2 John 1:4-5) and a second group known as "deceivers" (2 John 1:7).
2. The group of deceivers is made up of individuals (end of vs 7) who are opposed to Christ.
3. The particular denial is relating to Christ's coming in the flesh (beginning of vs 7).
4. This sets up the situation described in vs 10 "If anyone comes to you and does not bring this teaching [the teaching of Christ referenced in vs 9], do not take them into your house or welcome them."
5. To welcome someone at this point is established as bringing them into a teaching position in the church. We know this due to the relationship of the author (Elder vs 1) to the recipient (Lady vs 1 and Dear Lady vs 5). Her "children" (vs 4) meet together making up the church in her house. Notice house is not plural, but singular, (Oika in Greek and singular in form). While there is a general rule for churches, that general rule comes out from this particular pattern and rule as applied to this house locally written to here in 2 John.
6. The things that are forbidden in relating to this deceptive group are in verse 10 "take them in" (explicitly said), "welcome" (explicitly said), and "teaching" (which is implied since the deceivers "do not bring this teaching" - they must then bring another teaching).
7. When we apply this to our own varied contexts today we see that the local church is not to knowingly welcome those who teach contrary to the Gospel of Jesus Christ into our churches to spread their false gospels which are (and they are while propagating them) antichrist.
2 John is often in direct contradiction to the theology of "invite everyone to church!" and "How will people hear about Jesus unless they hear my preacher on Sunday?" - well....while the gospel does go forth through Lord's Day sermons, far more often it is beyond the gathering of believers that the gospel goes forward to unbelievers. The gathering of God's people is not a "public" free-for-all event despite what seeker-sensitive churches and public government policies say. Church gatherings are for the building up of the saints in the ministry of Christ. It is not an open debate hall, or a town hall meeting of listening circles where "everyone can be heard, and everyone can feel accepted". The gathering of the saints is a very special time of meeting wherein God gathers his people and meets in Spiritual communion together.
Faithful pastors and elders, those given oversight over the gospel teaching ministry (notice that 2 John is from "the elder" who is then giving instructions relating to hospitality and teaching) are to be discerning and judicious regarding those they invite to teach the gathered body of believers. Whether that is in some massive building, or in a house church, either way, elders are responsible for ensuring and encouraging that only the sound teaching of Christ goes forward and is held aloft for believers as we meet and worship.
Lest anyone say "This is very harsh and unloving" - be reminded that this letter is one which repeats and emphasizes that command which we have had since the beginning (vs 5) - that we love one another. To love one another is to lift Christ on high, obeying his commands. Christ has not given permission for false gospels that deny the incarnation, (or any other truth of the gospel) to be spread among his people. Just the opposite, we are to "continue in the teaching" (vs 9) rather than be dissuaded by deceivers. The most loving thing churches can do on Sunday is ensure that all ministry that is conducted is Christ-centered gospel ministry. There are not denials of the gospel going on, but instead the gospel is put forward early, often, and repeatedly among the gathered saints.
Quick Practical Applications
1. Don't invite gospel deniers into the church to teach/share/preach/speak up. It is worse for Christians to welcome gospel deniers than to invite holocaust deniers to a Jewish synagogue. Preachers/teachers/sharers/speakers are to be those called, empowered, equipped, and vetted for gospel ministry. This is 2 John's way of saying what Paul says to the Galatians "Even if an angel shows up giving you a different gospel, do not fall for it!"
2. When false teaching arises or is suspected in our churches, we must go to our elders and seek the next steps. Don't be a "long ranger" and act apart from those the Lord has put in oversight of your souls, work alongside and under their careful loving supervision.
3. Those who partner with gospel deniers are participants in their work. We (particularly those who are called to oversight ministry as pastors/elders) need to not only know where preachers/teachers/speakers are in their teaching regarding the gospel, but we also need to know how/when/where they are in league with others. Partnerships matter spiritually, someone may be a gospel minister, but if they are in league with the antichrist, we ought not to welcome them into our pulpits or places of gathering for teaching.
4. Real joy comes from being in union with God via Christ. Those who deny the gospel have no real joy. Any joy they claim or say they offer is counterfeit. True joy comes from knowing the truth and having the truth live in us.
5. Joy is connected to the truth of the gospel. Discerning the reality of the mystery of Christ revealed brings tremendous joy. Speculations and denials are surefire ways to confusion, darkness, and eternal death. An everlasting joy begins in the present age as we persevere in the truth of the gospel of Christ.
I hope something in these notes is of help to you! 2 John is always a JOY to go through with believers, both in preaching and in teaching opportunities.
If you have particular questions, I'm happy to interact as time allows. These are some of the general principles though from my own study and preaching over the years.