'Brotherhood' in the Bible

Be carefully on your guard lest there be any one who falls back from the grace of God; lest any root bearing bitter fruit spring up and cause trouble among you, and through it the whole brotherhood be defiled;

Do not neglect to extend hospitality to strangers [especially among the family of believers—being friendly, cordial, and gracious, sharing the comforts of your home and doing your part generously], for by this some have entertained angels without knowing it.