Live in Truth and Love: 2 John 1: 4-11.   
John rejoiced when he heard that believers were living according to the truth.  Truth is not an intellectual assent of some biblical facts but the life lived in the power of the indwelling Holy Spirit.  Agreeing on the truth does not mean living in truth.  Jesus is the embodiment of Truth, who came from the Father (John 1:14; 14:6). The Holy Spirit is the Spirit of truth. Truth is the reality of God and nonnegotiable. It is given for the obedience of faith (Romans 1:5). Believing the truth about Christ will set us free from sin and its influences (John 8:32). False teachers claimed that they have received new revelation that was different from the truth already given. They reject the once for all given truth that is to be defended (Jude 3).  Christians should love one another and obey the truth, the God’s Word. This love is the self sacrificing  love that seeks the good of others. Love and obedience will always go together. Having been loved by the Lord, we are to love others even when they seem not deserving it. False teachers taught that Jesus was divine only from the time of His baptism until His death.  They led many believers astray by their false teaching. They do not believe in the absolute deity of Jesus Christ. Whoever denies that Jesus came in the flesh is a deceiver and the antichrist. They don't understand the importance of Christ's incarnation.  John warns believers that they should be on guard and follow the teaching of the apostles. Failure to detect and reject error opens the door to serious problems in the church (1:8). Christians must be diligent to maintain the purity of the gospel for the sake of the glory of Christ and health of the church.  Only those who remain in the teaching of Christ are the true followers of Christ, Christians (John 8:31). Christians are warned not to show hospitality to false teachers. Anyone who supports and encourages false teachers becomes a partner in their evil work. 

​Conclusion:  2 John 1:12, 13.  
Although John could write much more to the chosen lady and children, he preferred to speak to them face to face.  He hoped to visit them soon so that their joy may be complete.  It shows how important fellowship is in the Christian life. John concludes the letter by wishing them greetings from the sister church. This is a brief letter that gives instruction on hospitality among Christians. In the first century inns were not suitable for missionaries to rest. So they were welcomed by fellow believers in their homes (Acts 16:15; 21:8, 16).  John warns believers against showing  hospitality to false teachers.  Christian love must be discerning. Christians must not have fellowship with false teachers.  God’s servants must meet the test of sound doctrines before they are welcomed and supported. The style and the vocabulary of the letter suggest that apostle John wrote this letter. It was written probably from Ephesus around A.D 90. This letter was addressed to a chosen lady and her children. ​”Lady” is a figurative name of a church.