[OP is asking whether or not she should attend her
sister's gay wedding]

I really don't see how attending a homosexual reception is any different than demon's destroying the masses. When Jesus approached the demons they acknowledged him, worshipped him, and trembled. Yet, then went on with their destruction. Your sister is saying I accepted Jesus, but I don't care what he says or that this is an abomination and they will spend eternally in hell. "I think"....no, we are Christians- "Christ like". We don't purpose to live contrary to his word. He lives in us and we live for Him.

God clearly states homosexuality is an abomination and that he has given them over to a reprobate mind. He also tells us that he will not be mocked and that they will go to eternal damnation. So, I am at a loss why a Christian would want to attend anything that has to do with something that is such an abomination to God.

I think you should take your cue from God's word, and your grandmother who obviously has some wisdom. As a Christian we are to be salt and light. We are to be in the world, but not of it. Judgement begins in God's house. Those that are his hear his voice. We aren't to partake in darkness- so obey God if he truly is your Lord and Savior.

I have 2 family members that are homosexuals. It is painful. I love them, but I know their eternal destination. It is their choice, but I don't go to attend their functions and 'celebrations' that are contrary to God's word. I love them. It pains me. But I live for Christ. God doesn't love them any less anymore than I do, but as God won't acknowledge their 'marriage' nor will I. Clearly this reception is for this purpose. How does one 'celebrate' and 'congratulate' a person living contrary to God's word???