The Apostle John said:

As for you, let that abide in you which you heard from the beginning. If what you heard from the beginning abides in you, you also will abide in the Son and in the Father (1 John 2:24 New American Standard Bible).

When I read this, my first thought is which beginning is John talking about. Is John talking about what's from the beginning of Jesus' ministry, starting with the baptism of John the Baptist (Acts 1:21-22)? In other words, is John talking about the gospel message that he and the other eleven apostles were to be a witness? Or, is John talking about what was from the very beginning -- the Word that was with God, was God, and Who created all things -- Jesus (Genesis 1:1, John 1:1-3).

I can see it both ways. But, when taken in context, I believe John is referring to what's from the very beginning. He's talking about humankind's fall and need for a savior. And, he's talking about the deity and appearing of the Lord Jesus Christ. That's what John means by saying:

By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God; and every spirit that does not confess Jesus is not from God; this is the spirit of the antichrist, of which you have heard that it is coming, and now it is already in the world (1 John 4:2-3).

Today, that which was from the beginning is under continual attack. We are told all religions come from the same source and it doesn't matter which one we chose. The temptation is to bend a little -- to see things in a different way. John says this is the spirit of the coming antichrist.

This brings us to another matter -- the issue of whether we'll be around to see the antichrist. Friends, if we won't be around, why did John bring up the subject? Why did John say:

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. 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 it would be shown that they all are not of us (1 John 2:18-19). 

This is what I believe. Here John is saying the same thing that Jesus said in Matthew 24:8-15, and the Apostle Paul said in 2 Thessalonians 2:3 -- the appearing of antichrists and the antichrist will be our sign of Christ's soon return. 

In the meantime, we are to hold on to something and not let it go.

What we heard from the beginning.