'Brother' in the Bible

From: Paul, called to be an apostle of the Messiah Jesus by the will of God, and from our brother Sosthenes.

But now I am writing to you to stop associating with any so-called brother if he is sexually immoral, greedy, an idolater, a slanderer, a drunk, or a robber. You must even stop eating with someone like that.

Instead, one brother goes to court against another brother, and before unbelieving judges, at that!

I (not the Lord) say to the rest of you: If a brother has a wife who is an unbeliever and she is willing to live with him, he must not abandon her.

But if the unbelieving partner leaves, let him go. In such cases the brother or sister is not under obligation. God has called you to live in peace.

In that case, the weak brother for whom the Messiah died is ruined by your knowledge.

Therefore, if food that I eat causes my brother to stumble, I will never eat meat again, in order to keep my brother from stumbling.

Now concerning our brother Apollos, I strongly urged him to visit you with the other brothers, but he was not inclined to do so just now. However, he will visit you when the time is right.