People of faith often use the phrase “God doesn’t make mistakes.” to justify transphobia. For the moment, we’ll set aside the offensive implication that there is something wrong with trans people, therefore, God having made them would somehow be “a mistake.” God, by definition, doesn’t make mistakes, but what does that actually mean in terms of human gender?
Consider intersex people. Depending on definitions and other factors, somewhere between one in a thousand to one in a hundred live human births are some degree of intersex. And since God doesn’t make mistakes, God made them this way for a purpose. The reason why is a mystery to us, but it clearly indicates that God’s plan for humanity isn’t as clearly divided into male and female as some would have us believe.
So, if one concedes that intersex people exist (no doubt at this point we lose some people; intersex erasure is so pervasive in western society that many don’t even know they exist), then that means that human gender is more complex than XX = female and XY = male. Those chromosome combinations aren’t the only viable ones, and chromosomes are just the tip of the iceberg. One gene on the Y chromosome triggers a cascade of changes, activating and deactivating genes across the entire genome. Genes (almost) all people carry, regardless of gender. Some of those genes regulate sex hormones, which are actually what drives the vast majority of developments that would be classically considered male or female. At any point in the chain, a mutation can alter the course of events. There a wide varieties of end results and efforts to push them into male or female boxes are decried as abusive by these people themselves.
So given that the physical attributes of gender (or sex if you prefer) are a lot more complicated and varied than a simple binary system, is it reasonable to assume that the neurological differences between genders isn’t? While this aspect of human development is less well understood (popular stories claiming scientists have found a genetic explanation for particular human behaviors generally overstate the actual research results), it is, in all likelihood, more complicated, not less than that of physical development. And so, variation is to be expected. And, not surprisingly, occurs at similar rates. While estimates of the number of trans people vary, they generally fall into the same one-in-a-thousand to one-in-a-hundred range that numbers of intersex individuals do. None of these people are “a mistake.”
So, in conclusion, God doesn’t make mistakes, but that doesn’t mean God endorses your transphobia. In fact, it says the opposite.