21I write to you, not because you do not know the truth, but because you know it, and you know that no lie comes from the truth. 22Who is the liar but the one who denies that Jesus is the Christ? This is the antichrist, the one who denies the Father and the Son. 23No one who denies the Son has the Father; everyone who confesses the Son has the Father also. 24Let what you heard from the beginning abide in you. If what you heard from the beginning abides in you, then you will abide in the Son and in the Father.25And this is what he has promised us, eternal life.
Whoa, this passage names all unbelievers as antichrists. Anyone who denies that Jesus is the Messiah is, quite logically, an antichrist. There are a lot of people who think they only need to believe in God, but notice what it says in verse 23: if you don’t acknowledge Jesus as Lord then you don’t have God, the Father.
I love how this passage ends with that greatest of promises—eternal life for believers.