The Bible states that mankind is depraved and has inherited that fallen depraved nature from Adam:
For if, by the trespass of the one man, death reigned through that one man, how much more will those who receive God's abundant provision of grace and of the gift of righteousness reign in life through the one man, Jesus Christ. Consequently, just as the result of one trespass was condemnation for all men, so also the result of one act of righteousness was justification that brings life for all men. For just as through the disobedience of the one man the many were made sinners, so also through the obedience of the one man the many will be made righteous (Romans 5:17-19, NIV).
As a result of the fall, sin entered into the world. People die. Our planet is polluted. There are wars, earthquakes, and famines. Everything wrong on planet earth is, somehow and some way, a direct result of that one sin way back in Eden. Although I'm all for a solution to pollution and world peace, and even though I am totally in favor of putting an end to hunger and earthquakes, the topic being addressed is sexual ethics: What's right? What's wrong? And Why? Therefore, I'm primarily concerned with answering the following question:
How would sex have been different if Adam and Eve had not sinned?
This question can be divided into various subcategories of questions:
- Did Adam and Eve have sex prior to the fall?
- Was marriage instituted before or after the fall?
- Did Eve have the ability to procreate before the fall? Or did she acquire the ability to procreate after the fall?
- Would mankind wear clothing today if there were no fall yesterday? (For an in-depth answer, see Does The Bible Condone Nudism? )