My brother recently got married to his non Muslim fiancee without her converting to Islam. This was done under civil marriage. Obviously, me and my family were unhappy with this and I know this is haraam. My brother is not a practicing Muslim and despite telling him of all the consequences he might face, he still went ahead with the marriage. My question is, how serious is this sin?
My family and I are deciding whether or not to attend his wedding dinner in 3 months time. My brother has not been close to us for the past few years as he has been staying with the girl's family house. You could say the relationship between my brother and us is somewhat strained for the past many years. The thing is if we attend, would it be seen as us supporting something that is haraam? Every day, I pray to Allah that he will be guided back to the right path.
Need your thoughts,thanks.