'Brethren' in the Bible

For I was greatly pleased when [some of the] brothers came [from time to time] and testified to your [faithfulness to the] truth [of the gospel message], that is, how you are walking in truth.

Beloved, you are acting faithfully in what you are providing for the brothers, and especially when they are strangers;

For this reason, if I come, I will call attention to what he is doing, unjustly accusing us with wicked words and unjustified charges. And not satisfied with this, he refuses to receive the [missionary] brothers himself, and also forbids those who want to [welcome them] and puts them out of the church.