'Brother' in the Bible

The one who says [he] is in the light and hates his brother is in the darkness until now.

The one who loves his brother resides in the light, and [there] is no cause for stumbling in him.

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.

By this the children of God and the children of the devil are evident: everyone who does not practice righteousness is not of God, namely, the one who does not love his brother.

not as Cain, who was of the evil one and violently murdered his brother. And {for what reason} did he violently murder him? Because his deeds were evil and the [deeds] of his brother [were] righteous.

Everyone who hates his brother is a murderer, and you know that every murderer does not have eternal life residing in him.

But whoever has the world's material possessions and observes his brother {in need} and shuts his heart against him, how does the love of God reside in him?

If anyone 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 is not able to love God whom he has not seen.

And this [is] the commandment we have from him: that the one who loves God should love his brother also.

If anyone should see his brother sinning a sin not [leading] to death, he should ask, and he will grant life to him, to those who sin not [leading] to death. ([There] is a sin [leading] to death; I do not say that he should ask about that.