Genesis 1:26-27

And God said, Let us make man in Our image, after Our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.
So God created man in His Own image, in the image of God created He him; male and female created He them.

God had already created night and day, the sea and the land, the flowers, grass and trees, the flying birds and the underwater creatures, and the animals that would creep all across the earth.  Everything was set in place...but something, or SOMEONE was missing!

Have you ever heard the saying, "Saving the best for last"? That is exactly what God did in creation week.  He waited until the very last to created His most complex, most unique, most "like Himself" creation.  He made sure to point out that He would make man in HIS image; not in the image of anything else that He had created.  There had been no duplicates up until the sixth day, so why duplicate now?  

God decided to make humanity male and female.  First, He created the man.  The fact that man was created first is significant.  I know that feminism has crept into the world and we don't like to acknowledge the importance of the fact that man was created first, but that's how God did it, and it is good. God made the man first because He is the leader, the head, the strength of the family, the patriarch, the one who stands between the world, which is doing its best to devour the family, and the family, which is a body that needs a head.  God does things in ORDER.

Next, God created the female.  He created her as part of the man, and she would eventually give birth to the man.  She would be the ice in his cool drink of water, the calm in his storm, the reasoning in his crazy, mixed up world.  She would come alongside him when everyone else turned their backs, she would whisper encouragement to him when it looks like all hope is gone.  She would feed him when he is hungry, keep him company when he is lonely, and present a castle in his home when the world treats him as an outcast.  She is the weaker of the two, but she possesses an internal strength  complements the male in very unique ways.  God knew exactly what He was doing.

This evil, dark and sinful world in which we live rejects the idea of the male-female relationship, within the confines of a holy marriage, which is the only God-ordained intimate relationship.  The world can reject it all they want; that is their choice.  But when the world stands before the Holy God, which they will, He will judge them based on what they believe about His Son, and what they did within the bodies that the LORD gave to them.  If they committed sexual immorality, which is any sexual act committed outside of a holy marriage between one man and one woman (which is also the ONLY definition of marriage) God will judge them based on that unrepented act.  1 Corinthians 6:9-11 says "Or do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived; neither the sexually immoral, nor idolaters, nor adulterers, nor effeminate, nor homosexuals, nor thieves, nor the greedy, nor drunkards, nor revilers, nor swindlers, will inherit the kingdom of God.  And such were some of you; but you were washed, but you were sanctified, but you were justified in the name of the LORD Jesus Christ and in the Spirit of our God."  God will not open His heaven to those who are involved in sexually immoral relationships without repentance.  He made them male and female for a reason, and He gave them sex as a gift to be exercised within a holy marriage.

If you were born male, when you stand before the LORD, He will judge you as a male.  If you were born female, when you stand before the LORD, He will judge you as a female.  He placed DNA within you that proves who He created you to be, and no matter how you dress, how many hormones you ingest, or how much surgery you have, NOTHING you can do will change who the Creator created you to be.  When a baby is born, it is either male or female.  The parents of that baby have no choice, and neither does the baby.  God's Word makes this plain and we would do well to heed God's Word.