Should I go to my friend's baptism?

I was recently asked by a friend if I would attend her baptism when she is 'born again' and I'm not sure whether or not I should go.

On the one hand I don't want to be the evil atheist who won't support her friend. I'm worried it might be rude to decline the invitation. On the other hand, I am completely against everything her church stands for, not only the claims it makes about God and the nature of reality, but also its stances in social issues such as its damaging anti-gay beliefs. 

I would have no reservations about attending a church wedding or funeral, but somehow this feels different. This is an explicitly religious ceremony which, whilst I support my friend's right to go through with it, I cannot support in itself. A wedding in a church could be, to me, a celebration of two people's relationships and a funeral could be a celebration of the person's life and an expression of how they will be missed. This baptism ceremony would be a celebration of the brainwashing my friend experienced from childhood and her acceptance of a flawed belief system that leads to prejudice and intolerance. I feel my presence would signify that I condone this and give my friends yet another chance to convert me. 

However, as an atheist I know that a baptism doesn't really do anything at all. It's just someone being dunked in a pool. She's already a believer in ridiculous things, intolerant of the lgbtq community and an opponent of science. I also want to show my friends that I can be a good person, a friend, and be a part of their lives even if I don't share their beliefs. 

Does anyone have any advice? Have you ever been faced with this problem?