In his letter to the Galatians Paul says, “There is neither Jew nor Gentile, neither slave, nor free, nor is there male and female, fo r you are all one in Christ”-Paul seems to be saying that for Christians gender identity has no importance, therefore changing one’s gender is off little importance
Alternatively a transgender person could claim that God created them as a whole, with the nature of one gender and the body of another, giving them the responsibility of choices about how to live their life.