There's lots of effort today to define men and woman as the same. Exactly the same. Exactly. However, the Bible says men and women are equal in value but different in creation. Genesis 1:21 says, "So God created man in his own image, in the image of God he created him; male and female he created them." God created males and females. Trying to make males and females exactly the same strips away unique aspects of God's design to create two kinds of humans--males and females.
No matter how hard we try, we can't escape the reality of God's creation.
Take the Olympics for example. At the time of this post, the fasted 100-meters ran by male (a person with an x and y chromosome) was run by Usian Bolt. He did it in 9.63 seconds. The female record holder (a person with no y chromosome) is Florance Griffith-Joyner. She ran the 100-meters in 10.62 seconds. In the world of the 100-meter sprint, that's a large gap. It's a difference.
Imagine if a person with an x and a y chromosome (typically called a male) were to self-identify as a female and run in the 100-meter female race. What if it were Usian Bolt? What if this happened in boxing? Would anybody be okay if Mike Tyson self-identified as a female and went into the ring with an actual female with two y chromosomes? I think the world would cry, "foul." In fact, the Olympic Committee has had to write a policy for transgendered athletes, to deal with God's created plan. (You can read that policy here.)
No matter how hard we try to define the terms as we want them, God, the Creator, is still the one who set the conditions. Men and women, according to God are equal in value but different in creation. We can try to make men and women the physically the same in creation, but in the end, God sets the terms. Because God is the creator.