Of all the powers given to mankind by God, the one most like God Himself is the power to create offspring. The sexual union of the man and woman resulting in children is a power so great it is called God's reward. (See Psalms 127: 3.) God's covenant with Abraham was based upon a numerous posterity. (Gen. 22: 17.)
Sex involves not only "knowing" (i.e., intercourse) between a man and woman (Gen. 4: 1), but also the woman "conceiving" a child (Id.). Sex also includes the woman bringing forth the child, and the father then naming the child (Matt. 1: 25.) It includes teaching the child the ways of God (Deu. 6: 6-7). It extends to a parent's duty to provide care, food, clothing and shelter for the child as well. (1 Tim. 5: 8.)
When the child is raised, the child then is obligated to honor and care for the parent. (Deu. 5: 16.) The cycle binds together generations in care, nurture and honor, altogether a godlike process. (Enos 1: 1.)
In a word, sex is life. It is the entirety of life. It produces and provides for generation after generation in a godly connection between man, woman and God.
If sex is separated from the entire scope of the Divine order, and redefined to be nothing more than orgasm, then it ceases to be life and becomes chaos and death. For example, if the ability of a homosexual union to produce physical gratification for the participants is regarded as the same thing, it not only fails to comply with the Divinely ordained order, it results in death. Homosexual unions produce no offspring and the participants go down to the grave childless. Their sexual powers have failed to result in creation, order, or fulfilling the pattern for life to continue.
If sex is separated from the entire scope, then children are born unwanted and are not raised with the care, love and sacrifice of the parents. They are not taught in the ways of God. They become less than what they were intended to be because they have inherited less than God intended for them to inherit.
Our society has largely confined its understanding of sex to nothing more than physical gratification. It is an orgasm and nothing more. Once we loose that single component from the Divine order, we have changed godlike creation into disorder and chaos. Ultimately it is the difference between life and death.