1 John 2:20-23

But you have an anointing from the Holy One, and all of you know the truth. I do not write to you because you do not know the truth, but because you do know it and because no lie comes from the truth. Who is the liar? It is the man who denies that Jesus is the Christ. Such a man is the antichrist—he denies the Father and the Son. No one who denies the Son has the Father; whoever acknowledges the Son has the Father also.

(v20-23, NIV)

Those who are believers in Christ Jesus have received the Holy One. The Holy One is the Holy Spirit who is the counselor and helper. In addition, we all know the truth. This truth that John is referring to is the truth that Jesus is the Christ. John was just talking about antichrists. These antichrists may come to deceive you. They may distort or twist the truth. The truth that we receive as believers who have received the anointing from the Holy One is that Jesus is the Christ.

The antichrist is a liar, distorting the truth. The antichrist denies that Jesus is the Christ. By doing so, he is denying both the father and the son. They may try to deceive you saying that they have the father or they have the son or that they know the father or that they know the son. If someone denies the son by denying that he is the Christ, then this person does not have the father.