'Brother' in the Bible

Paul, called to be an apostle of Jesus Christ through the will of God, and Sosthenes our brother,

But now I have written unto you not to keep company, if any man that is called a brother be a fornicator, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner; with such an one no not to eat.

But brother goeth to law with brother, and that before the unbelievers.

But to the rest speak I, not the Lord: If any brother hath a wife that believeth not, and she be pleased to dwell with him, let him not put her away.

But if the unbelieving depart, let him depart. A brother or a sister is not under bondage in such cases: but God hath called us to peace.

And through thy knowledge shall the weak brother perish, for whom Christ died?

Wherefore, if meat make my brother to offend, I will eat no flesh while the world standeth, lest I make my brother to offend.

As touching our brother Apollos, I greatly desired him to come unto you with the brethren: but his will was not at all to come at this time; but he will come when he shall have convenient time.