Heterosexuality involves the union between two people of different genders. It is the natural connection between two human beings and animals in order to reproduce. Heterosexual attraction is natural; that is, men for women, and women for men. Heterosexual union within marriage is the only form of sexual activity endorsed by God as His Word as revealed in the Bible. It is the opposite of homosexuality.
Theories on how one becomes a heterosexual
God created man in his image. Man was mortal, and thus had to procreate in order to continue the species. Two men were not suitable to God for this, so God made woman from man. And so, man continues to be heterosexual due to the correct genetic information being passed down from Adam and Eve. Those who choose homosexual sex reject the natural order and superior genetic line established by God's creation.
- Genesis 1:26 ESV