“You stood aloof.” The people of Edom had seen what was going on and the attacks on Jerusalem, but instead of helping their brothers, they stood off and watched, and even helped. Read Obadiah 1:11.
“On the day that you stood aloof, On the day that strangers carried off his wealth, And foreigners entered his gate And cast lots for Jerusalem- You too were as one of them.
Obadiah 1:11 NASB
The people of Edom had seen what was going on and yet they did not do anything to intervene. In fact, they were even part of the group attacking. Now God is going to hold them accountable for those actions. And since they attacked their brothers, because of the relationship, they are going to be more responsible for these types actions.
What we do matters, but it also matters who we do it against. If there is more to the relationship, then there will be more consequences for the sin. Who have we sinned against lately and what is our relationship with them? How can we repent and make it right?