Dear children, the last hour is here. You have heard that the Antichrist is coming, and already many such antichrists have appeared. From this we know that the end of the world has come.
These people left our churches because they never really belonged with us; otherwise they would have stayed with us. When they left us, it proved that they do not belong with us.
But you are not like that, for the Holy Spirit has come upon you, and all of you know the truth.
References for 1 John 2:20
So I am writing to you not because you don't know the truth but because you know the difference between truth and falsehood.