Hating your brother is not the way of Christ

The one who says he is in the Light and yet hates his brother is in the darkness until now.
1 John 2:9

But the one who hates his brother is in the darkness and walks in the darkness, and does not know where he is going because the darkness has blinded his eyes.
1 John 2:11

Everyone who hates his brother is a murderer; and you know that no murderer has eternal life abiding in him.
1 John 3:15

If someone says, “I love God,” and hates his brother, he is a liar; for the one who does not love his brother whom he has seen, cannot love God whom he has not seen.
1 John 4:15

"Hating your brother in 1 John goes beyond simply not preferring him; it signifies a rejection of love and a failure to embody the love that God commands. True love for others is essential to a genuine relationship with God." (1 John 4 Biblehub, Bibleref.com)

"Hatred towards a brother, in this context, refers to animosity or lack of love towards fellow believers." (1 John 2, Biblehub)

"In the context of 1 John, "hate" refers to a strong aversion or hostility towards another person, particularly a fellow believer. It is not merely about not preferring someone; it implies a deeper emotional and moral rejection." (Biblehub)

Does hate for other Christians mean that the hater is not a Christian?

"Yes, according to 1 John, hating your brother suggests that you are not truly abiding in Christ, as love for others is a fundamental aspect of being a Christian. The text emphasizes that those who hate are in darkness and do not possess eternal life." (Bibleref.com, Buildingjerusalem.blog)