I recommend reading the very good article, Sex without bodies, in Christianity Today. A common theme in the LGBT movement is to value someone’s personality or soul and to devalue the physical body. They believe in changing the body to match what is inside, because it is only what is inside that counts. This is totally contradictory to the Christian faith.
The Bible affirms that God made us as men and women, both made in his image. Together we reflect God. (Genesis 1-2). Our bodies are fallen and broken but still essentially good. They matter. Our bodies are part of our identity, part of who we are. Human beings are body and soul, and without both, we are not fully human. We must value both. God cares about what we do with our bodies. For Christians, our bodies are temples or houses of the Holy Spirit. God wants us to take care of our bodies, and for us to be healthy. He wants us to live as men and women, the people he created us to be.
This is why the incarnation of Jesus and the resurrection from the dead are some of the most important of all Christian beliefs. Think about it. God didn’t just appear to be a man and live among us. He didn’t just talk to us from the sky. He became flesh and blood, and was even born as a baby! Jesus, the God-man, walked the earth, ate, pooped, cried, laughed, and lived bodily. This is one of the most amazing mysteries, God made flesh. But it is so beautiful. It affirms how much God cares for us. It affirms the lengths God would go to be with us so intimately. And it shows us how important and GOOD bodies are. Bodies aren’t bad. They are good. Good enough for our God to take on flesh.
And the resurrection of the dead is equally important. When we die, our souls will go to Heaven to await the resurrection, but even though that time will be so sweet, as we will be with Jesus, we will be waiting for the resurrection, for our bodies that will be new and perfect, but still look like our old bodies in some ways. Jesus rose from the dead and conquered death. He didn’t just die for us so that our souls can float to heaven. He rose from the dead as the first-fruits so that we can also be raised from the dead to take on new wonderful bodies (1 Cor. 15).
Our bodies are good. They matter. They are part of us. We can’t just do whatever we want with them.