I have added a couple of posts arguing that Christians, American ones in particular (though I am sure we could all do better), should act in more solidarity with others, particularly the poor and underprivileged. Here are some bible verses to back up that position which talk of brotherly love (fraternity) for others:
The commandments, “You shall not commit adultery,” “You shall not murder,” “You shall not steal,” “You shall not covet,” and whatever other command there may be, are summed up in this one command: “Love your neighbour as yourself.” – Romans 13;9
This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers and sisters. – 1 John 3:16
Speak up for those who cannot speak for themselves, for the rights of all who are destitute. – Proverbs 31:8
Keep on loving one another as brothers and sisters. Do not forget to show hospitality to strangers, for by so doing some people have shown hospitality to angels without knowing it. Continue to remember those in prison as if you were together with them in prison, and those who are mistreated as if you yourselves were suffering. – Hebrews 13:1-3
Is not this the kind of fasting I have chosen:
to loose the chains of injustice
and untie the cords of the yoke,
to set the oppressed free
and break every yoke?
Is it not to share your food with the hungry
and to provide the poor wanderer with shelter—
when you see the naked, to clothe them,
and not to turn away from your own flesh and blood? – Isaiah 58:6-7
I will add more as I come across them.