Answer
Until the 1950s, the idea of differentiating between sex and gender was completely foreign to the medical and psychological communities. After all, aside from extremely rare instances, every human being has either two X chromosomes, and is therefore biologically female, or an X and a Y chromosome, and is therefore biologically male. It was not until the past decade or so that a distinction between sex and gender became popularized. Popular culture and postmodern psychology, however, do not change the fact that human beings are either XX or XY. No amount of hormone therapy or surgery can change that fact.
Adding to the confusion is the multiplication of alternate gender options that have appeared in recent years. There are now upwards of 50 gender options, including, but not limited to the following: agender, androgyne, androgynous, bigender, cisgender, gender fluid, gender nonconforming, gender questioning, gender variant, genderqueer, non-binary, pangender, transfeminine, transmasculine, transgender, and transsexual. If those options are not sufficient, many surveys also include choices such as “neither,” “other,” and “none of the above.”
The closest the Bible comes to mentioning gender dysphoria is likely in its condemnation of transvestitism in Deuteronomy 22:5, its mention of certain men being born eunuchs (born with abnormal sexual function) in Matthew 19:12, or its consistent declaration of the sinfulness of homosexuality (Leviticus 18:22; 20:13; Romans 1:26–27; 1 Corinthians 6:9; 1 Timothy 1:10).
The Bible nowhere mentions a man believing himself to be a woman, or vice versa. The Bible is explicitly consistent in equating gender with biological sex. Biblically speaking, human beings are male or female. There is no gender spectrum or continuum even hinted at in the Bible.
With that said, the Bible does teach that sin has devastating effects on humanity (Genesis 2:17; 6:5; Judges 17:6; Psalm 51:5; Romans 3:10–23; 8:22). If, in this fallen world, males can be born eunuchs and a small percentage of people can be born with hermaphroditism, then it is reasonable to assume that sin could also impact the aspects of our being that determine sexual attraction and/or gender identity. If people are born with all sorts of other birth defects, it is dubious to claim gender dysphoria could not also be a birth defect.
At the same time, sins such as anger and lust, even though they can have a biological component, are still sins. Even if there is a legitimate biological/genetic basis to a certain person’s gender dysphoria, the fact remains that embracing that dysphoria is sinful.
As Christians, we should show grace and compassion to those struggling with transgenderism. We should never forget that every human being, male or female, is created in the image and likeness of God. We should speak the truth that there are only two genders while also demonstrating love to those struggling with gender dysphoria (see Ephesians 4:15).