Brothers, Don’t Doubt

I recently echo the same thoughts about trust and doubt.
The moment sang the opening line, I melted.
When he address his 兄弟, I could felt the closeness, the brotherhood and the strong bond.

兄弟 做一世
犧牲小我 早已成慣例
共你講過 到下輩子一起創世

While I admire the brotherhood feel in this song, but I also felt sad at the same time.
Who still believes and stick to their brothers?
Where are the loyalty? Where are the trust?