<p>2:19- see on Mk. 14:68; Lk. 22:31; Jude 19.</p><p><em>They went out from us but they were not of us. For if they had been of us, they would have continued with us; but they went out, that they might be revealed, that all these are not of us</em>- This is the language of Judas going out into the night to betray the Lord. As noted on :18, the antichrists have some similarities with &quot;the man of sin&quot;, who as &quot;the son of perdition&quot; is also based upon Judas. There was a conscious campaign of infiltration of the church by Judaist false brethren (Gal. 2:4). According to many of Paul's letters, they enjoyed fair success in destabilizing the churches Paul founded. But in the community John had founded and is writing to, they &quot;went out from us&quot;. Their exit revealed them for who they were. The implication is that those who wilfully leave the community of the body of Christ are effectively leaving Him. It is likewise no less a sin to exclude members of that body from association with it. 3:9,10 use the same word in saying that the revealing of the sons of God and those of &quot;the devil&quot; the Jewish system is in whether they love or hate. Going out from the community of believers is not abiding in love. Their exit revealed them; and the revelation is in whether we love or hate (3:9,10).</p><p>&quot;All these are not of us&quot; can be rendered &quot;they were not all of us&quot; (AV), and this makes the reference to the Lord's words about Judas even clearer. He said that &quot;not all&quot; of them were cleansed because of Judas being the one amongst the &quot;all&quot; who would betray Him (Jn. 13:10,18).</p>