Hi Magenta.
HAPPY BIRTHDAY!!
Let's do 1 John 2:19. How could anyone say that anyone was not really saved, that's the question.
For starters, I trust the Apostle JOHN, but here goes...
1 John 2 is titled that Christ is our advocate.
What's interesting is that I keep being told that we don't have to do works, but here in the chapter you refer to, once again we're told that we ARE to keep the commandments.
1 John 2:4
The one who says he has come to Christ and does not keep His commandments is a liar - John said this, not me.
verse 5: But whoever keeps His word, in him the word of God has truly been perfected. The one who says he abides in HIm, must walk in the same manner.
1 John 2:18-19 New American Standard Bible (NASB)
18 Children, it is the last hour; and just as you heard that antichrist is coming, even now many antichrists have appeared; from this we know that it is the last hour.
19 They went out from us, but they were not really of us; for if they had been of us, they would have remained with us; but they went out, so that [a]it would be shown that they all are not of us.
1 John 2:18 is telling us that many anti-Christs have risen. By this, Peter felt they were near the end of the world.
These anti-Christs went OUT FROM AMONG the believers, but they were not really of the believers.
Someone who simply believes or does not believe in Christ is not an anti-Christ.
These people were the wolves in sheep's clothing, trying to convince Others that Jesus was not The Christ, or God.
Mathew 7:15-20
Jesus was speaking here about people, ministers, who would try to infiltrate the Church by being wolves in sheep's clothing.
verse 23, interestingly says that the one who denies the Father does not have the Son. So, as I said in a different post, God wills that all know Christ, but not all do. If one denies the Father, he also denies the Son and so is lost.