2 John 1:10,11

If there come any unto you Either as a teacher or a brother; and bring not this doctrine Of Christ, namely, that Jesus Christ, the Son of God, did come in the flesh to save mankind; or advance any thing contrary to it, or any other branch of Christ's doctrine; receive him not into your house Either as a teacher or a brother; neither bid him God speed Give him no encouragement therein; for he that biddeth him God speed That gives him any encouragement; is partaker of Is necessary to; his evil deeds We may infer, from what the apostle here says, 1st, That when those who professed to be the disciples of Christ came to any place where they were not known to the brethren who resided there, nor were recommended to them by some with whom they were acquainted, they made themselves known to them as the real disciples of Christ, by declaring their faith. This shows the propriety of the apostle's advice to this pious matron and her children. 2d, That as the Christians in those days exercised hospitality to their stranger brethren, who were employed in spreading the gospel; so the Christian sister to whom the apostle wrote this letter, being probably rich, and of a benevolent disposition, thought herself under an obligation to supply the wants of those strangers who went about preaching. Wherefore, to prevent her from being deceived by impostors, the apostle here directs her to require such teachers to give an account of the doctrines which they taught; and if she found that they did not hold the true Christian doctrine, he advised her not to receive them into her house, nor to give them any countenance. And this advice of the apostle was certainly perfectly proper, because they who entertained, or otherwise showed respect to, false teachers, enabled them the more effectually to spread their erroneous doctrine, to the seduction and ruin of those whom they deceived.