2John 1:9-13 Whosoever transgresses, and abides not in the doctrine of Christ, has not God. He that abides in the doctrine of Christ, he has both the Father and the Son. If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him God speed: For he that bids him God speed is partaker of his evil deeds. Having many things to write unto you, I would not write with paper and ink: but I trust to come unto you, and speak face to face, that our joy may be full. The children of thy elect sister greet thee. Amen. 

‘Whosoever transgresses, and abides not in the doctrine of Christ, has not God. He that abides in the doctrine of Christ, he has both the Father and the Son’ any person who sins and does not remain in the truth, doesn’t have God. He who does not sin and who remains in the truth has both the Father and the Son. This warns of the possibility of backsliding and losing rewards (2Jn. 1:8), as well as losing God and Christ.

‘If there come any unto you, and bring not this doctrine, receive him not into your house’ If any man poses as an apostle or Christian teacher and does not teach the true doctrine of Christ – the incarnation, the death, burial, and bodily resurrection of Jesus Christ – do not receive him or give him entertainment in your home. Do not even bid him Godspeed. If you do, you are a partaker [give approval (Rom. 1:32)] of his evil deeds and will be punished with him for the same sins (2Jn. 1:10-11).

‘Neither bid him God speed’ Scriptures warn against fellowship and friendship with non-believers: not to get counsel from the ungodly, or to follow in the same ways as sinners or workers of iniquity, or to sit with those who mock the Word of God, those who are vain or wicked (Ps. 1:1-6; 6:8; 26:4-5; 1Jn. 2:15-17) and not to go in with dissemblers [hypocrites]. Not to cast your lot with criminals and sinners when they entice you to follow in their wicked ways (Pro. 1:10-15). We are warned to stay away from foolish and angry people and not to be friends with them (Pro. 9:6; 14:17; 22:24); to stay away from backslidden Christians and those who walk disorderly (Matt. 18:15-17; 2 Thess. 3:6; 2Jn. 1:9-11) and those that cause divisions and offences (Rom. 16:17). We cannot listen to false teachers’ teachings and think we will afterwards understand God’s Word at all (1Tim. 4:1-2; 6:3-5; 2Tim. 2: 16-17; 2Jn. 1:10). We cannot have company with those who do not obey God’s Word (2Thess. 3:14-15); be in business, friendship or fellowship with unbelievers or those who live in unrighteousness and darkness (2Cor. 6:14-18). We cannot keep company or eat with fornicators, covetous, heady and high-minded people, idolaters, railers, drunkard, or extortioners (1Cor. 5:9-11). Stay away from those who are lovers of themselves; boasters; proud, unthankful, unholy people; blasphemers; disobedient to parents; those without natural affection; trucebreakers; false accusers; incontinent; fierce people, despisers of those who are good traitors, those who love pleasure more than God and the hypocrites – those who have “a form of godliness, but deny the power thereof” (2Tim. 3:2-5).

‘The children of thy elect sister greet thee.’ This Scripture must be understood as all other greetings: The followers of Christ greet you our sister (can’t say brother here, even though she is clearly part of the body of Christ which is represented by the male term ‘brethren’ (Heb. 2:11; 1Pet. 2:17; 5:9).