1 John 4:2-3

2 Here is how you recognize the Spirit of God: every spirit which acknowledges that Yeshua the Messiah came as a human being is from God,

3 and every spirit which does not acknowledge Yeshua is not from God - in fact, this is the spirit of the Anti-Messiah. You have heard that he is coming. Well, he's here now, in the world already!