'Brethren' in the Bible

Laying these things before the brethren, thou wilt be a good minister of Christ Jesus, nourished with the words of the faith and of the good teaching which thou hast fully followed up.

Rebuke not an elder sharply, but exhort him as a father, younger men as brethren,

And they that have believing masters, let them not despise them because they are brethren; but let them the rather serve them with subjection, because they are faithful and beloved, who profit by the good and ready service rendered. These things teach and exhort.