Man has thought up different viewpoints on human sexuality.
The many evolutionary and materialistic viewpoints fit in here as well as many religious perspectives.
All of these views have as their common point that man has through his own thinking thought up the proper function and expression of sex in our world. They are dependent on their own viewpoint. Their views are necessarily subjective. This is not just true for Playboy's concept for sexuality - self pleasure, but also the concepts of different religions. Some propose celibacy while others say very little. But their sources always depend upon what man has thought about these matters.
The result of these viewpoints is a conflicting, faulty and disastrous life perspective. For example, the materialistic viewpoint denies any outward design or purpose of human sexuality. They believe the world is full of coincidents and accidents. Man guesses and tries to understand. Meanwhile man pays the painful price of sin.
God has revealed His viewpoint on human sexuality.
God as the creator of man has spoken quite clearly in the Bible on many issues including our sexual natures. He not only has told us how male and female were originally made different, but on how our sexual nature affects our behavior.
God only has one viewpoint. In a real sense He has given us the handbook on the human race. God designed man and woman and has let mankind in on the secret to His design. Now it makes every bit of difference on the quality of our life as to how much we pay attention to what our Creator has said.
The result of this viewpoint is a cohesive and beautiful design. God has declared everything that He has made to be 'good' including man and woman along with their sexuality. With design there is purpose. We have confidence that God wants to reveal this design to us and be fulfilled.