2:18 John probably used a different Greek word translated "children"(paidia, also in v. 12) because it implies a child who learns. His readers needed to learn what he now revealed.
In the drama of human history all of John's readers including ourselves play our part in the last act. Throughout the New Testament the writers regarded the present age before the Lord's return as the last hour or the last days. This is the final period before the Lord Himself breaks into history again. Then the first stage of the new age will be judgment (the Tribulation) and the second stage blessing. In the second stage Jesus Christ will rule directly over human beings first in the Millennium and then in the new heavens and the new earth.
The revelation concerning the appearance of the world ruler who will exalt himself against God had reached John's audience (Dan. 11:36-45; 2 Thess. 2:3-5; et al.). However even as John wrote many little antichrists, people who exalt themselves against God, had arisen. John saw this as evidence that the appearance of theAntichrist was not far away. Antichrists are those who oppose Jesus Christ and His teachings, not just people who profess to be the Messiah.88
2:19 Those who were opposing Christ had gone out from "us."Probably "us"means the apostolic eyewitnesses as elsewhere in this epistle (cf. 1:1-5; 4:6). This would mean that these false teachers had gone out from among the apostles, not that they were apostles themselves, claiming that their message was what the apostles endorsed (cf. Acts 15:1; 2 Cor. 11:5). "Us"may include the Christian community at large. The physicalseparation of these men from the apostles and the faithful eventually illustrated their doctrinalseparation from them.
"From other references to antichrists' in this letter it is evident that when the writer uses this term he means the heterodox ex-members of his own community: those who, in one way or another, were denying the true identity of Jesus, and the fact of God's saving activity mediated to the world through him."89
". . . it is possible, in this instance, that those who later allowed their heretical thought and actions to run away with them (when it could obviously be said, ouk esan ex emon, they were not of us') were in the first place believers with a genuine, if uninformed, faith in Jesus."90
". . . a person who makes a genuine confession can be expected to persevere in his faith, although elsewhere John warns his readers against the danger of failure to persevere [cf. v. 24; 2 John 8]."91
Whereas divisions within Christendom create obvious problems, God causes some good to come out of them by using these divisions to clarify doctrinal differences and deviations from the truth.
