'Brother' in the Bible

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

but as it is, I wrote unto you not to keep company, if any man that is named a brother be a fornicator, or covetous, or an idolater, or a reviler, or a drunkard, or an extortioner; with such a one no, not to eat.

but brother goeth to law with brother, and that before unbelievers?

But to the rest say I, not the Lord: If any brother hath an unbelieving wife, and she is content to dwell with him, let him not leave her.

For the unbelieving husband is sanctified in the wife, and the unbelieving wife is sanctified in the brother: else were your children unclean; but now are they holy.

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

For through thy knowledge he that is weak perisheth, the brother for whose sake Christ died.

Wherefore, if meat causeth my brother to stumble, I will eat no flesh for evermore, that I cause not my brother to stumble.

But as touching Apollos the brother, I besought him much to come unto you with the brethren: and it was not all his will to come now; but he will come when he shall have opportunity.