Yesterday, we learned that there will be an Antichrist; not only that, but that we would be able to recognised that we are living in the last days because many would leave our churches as types of antichrists. Let's continue to read 1 John 2;
21 So I am writing to you not because you don’t know the truth but because you know the difference between truth and lies. 22 And who is a liar? Anyone who says that Jesus is not the Christ. Anyone who denies the Father and the Son is an antichrist. 23 Anyone who denies the Son doesn’t have the Father, either. But anyone who acknowledges the Son has the Father also.
An antichrist is anyone who denies God the Father and God the Son (Jesus). They are liars because they refuse to acknowledge the truth - Jesus is the truth. It is one thing to be ignorant or not know; however denial is to choose not to accept what is being revealed.
As believers, we know the the truth. We know that Jesus truly is the Son of God who died for the sins of the whole world and rose again the third day. Because we have acknowledge the Son, we also have the Father, for Jesus is the ONLY way to the Father. If a person does not have Christ and refuses to acknowledge Him, then they do not have the Father either. That is the truth.