It's been stated there's a double standard within Christian thinking, in that we talk against discrimination in racism, but yet discriminate against homosexuality, and this seems like a contradiction to many. This subject, which no matter how you identify this, you will more than likely offend someone, which I'll try to approach in kindness towards all, because all of us are affected in some way.
Let me first state that the reason Christianity is opposed to racism, is because the individual is sacred no matter what race you or I come from. God places the ultimate value in human life and the soul of every individual. But also within Christianity, sexuality is also “sacred” and should not be violated, but considered a treasured gift from God. So if both are sacred, both are to be protected and held with respect and high regard. Protecting the individual made in the image of God, as well as marriage, where God has made man and woman for each other.