John speaks tenderly to believers of severe dangers which they will have to pass through, but which by the help of God they are more than able to face.
God has a plan which determines the history of this world, and he has explained in his word how it will unfold. Although we cannot tell our precise position in this plan, we can see enough to draw encouragement that his plan is on track and all things move towards their perfect conclusion.
Wherever the Lord Jesus Christ, the incarnate Son of God, is denied, there is the spirit of antichrist. This is clearly seen in the cults, but it is also seen in those who deny his teaching and his divine authority. They are antichrists because that explicitly attack him and are wilfully against him.
How can there be many antichrists when prophecy speaks of one antichrist at the end of time? Those many antichrists include all who are inspired by the same satanic spirit of apostasy and bring the same error into the world, but we still wait for the manifestation of the man of sin ‘who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God’ (2 Thessalonians 2:4).
To some, John writes as if he believes he is living in the last decades of earth’s history. They choose to interpret his words in this way because they wish to prove that the apostles were fallible men with limited outlooks, rather than those who wrote under inspiration. John however is describing the general characteristics of the last age, and elsewhere in his writing makes clear that definite significant events must take place before the end. Paul also warns the churches not to believe the Day of the Lord has come until certain landmark events have taken place. The apostles benefited from Christ teaching on the end times (Matthew 24, etc.) in which the Lord warned against prematurely concluding the end had come. The gospel must first be preached to all nations, there must be a great falling away, the antichrist must come, and the stability of the earth must be shaken.