Transgenderism fits remarkably well into the Christian notion of human beings as creatures made in the image and likeness of God.
Now, we could make this very easy. In fact, the sheer simplicity of the idea is what makes the anti-trans rhetoric in religious communities so bizarre. God is genderless, human beings made in God's image have no innate gender and don't need any gender at all, and so human beings who have transcended the gender others assigned them are closer to God's image. Case closed. But there is a little more profound, even transcendent, meaning to be extracted here.
While we've gotten behind the terms, most of us have not sufficiently explored the meaning of several theological concepts which we take for granted, including the "image of God."
Since God is a formless, immaterial being, there is little chance that this means that human beings physically look like God. Actually, we only really understand God in terms of action. Recall that God's name is "I am." Furthermore, within Christian scripture, God's kingdom can best be depicted through parables rather than through direct description. Thus God, and to exist in God's likeness, can be understood as activity.
If God is activity, then creation, God's work, is not done. As free agents, we take part in this creation. As beings in God's image, we are creators. We aid in the building of the kingdom of God. We are not sitting here waiting for some static afterlife; we are growing to integrate more completely and closely with God.
Allow me to explain this idea a little further. According to Christian scripture, God is "over all and through all and in all." Thus God is not a distant creator; rather, God creates immanently. Who better to create than human beings? We are creating ourselves, creating the kingdom which we make up. Eventually, theology tells us, we will become fully integrated with God in what is viewed as Paradise. Yet I would suggest that since God's essence is present in human beings, we actively develop toward this on our own by developing and tapping in more closely to the divine within us. As a collective of humans now, we develop toward non-distinctive, full integration into God.
As we create more and more, and develop our creations, we also become more and more like God, and make our integration with God fuller and fuller- without passively anticipating this in the afterlife.
Transgender individuals have moved beyond our limitations. No longer held down by confining structures, they have begun to transcend that which makes human beings different from a genderless God. They are more fully tapping into their identity as beings in God's image, as creators who are not limited by the restrictions placed upon them.
Of course, spirituality and divinity is a mystery. There is no reason why any individual would need to identify with this spiritual idea. Yet it is necessary to recognize not only that Christian people of faith should accept the transgender community, not only that they should love them, but that they should even revere them as people particularly in touch with the more spiritual, transcendental part of the human person.