Verse 15: For without are dogs, and sorcerers, and whoremongers, and murderers, and idolaters, and whosoever loveth and maketh a lie.
These all were the aggregation of the enemies of Christ and the saints and the persecutors of the church and their followers. The characters of all who were without the city were in contrast with all who were within it. The expression without are dogs had the implication that all who were without were of that classification, a term of various connotations. It was descriptive of the evil and impious characters that inhabit the outside.
Among the Jews the dog was typical of that which was unclean and vile. The Mosaic law decreed that the hire of a harlot and the price of a dog were abominable to God and were not acceptable for the offerings and the vows of the law. (Deuteronomy 23:18) Paul warned the Philippians to beware of the dogs (Philippians 3:2) which meant the cautious avoidance of Gentile influence and affiliation. The Jews called the Gentiles dogs; but here the unbelieving Jews had so classified themselves and the term had boomeranged and fallen back upon them. Jesus said to his disciples; “ Give not that which is holy to the dogs,” meaning that the pure principles of his teaching should not be compromised or mixed with the inferior philosophies and practices of the heathen world surrounding them. None of these evil things could enter the city of God--all dogs were without.
For comments on the terms sorcerers, whoremongers and liars turn to chapter 21:8,27. These were terms to designate heathenism and to define their practices; and these words of John constituted a pronouncement for the eternal exclusion of all classes which these evils represented, and of all who do not obey his commandments--the gospel which Jesus Christ had commissioned his ambassadors to preach to all the world.