A: This is a great question, and always timely, as relationship with others is probably the most important thing we can do while we are on earth. And, the loving relationship of man and woman is of extreme importance to most of us.
Ideally, sexual activity is best practiced between two people who love each other and who have joined themselves in a loving relationship that includes marriage and family. Of course, this ideal is not always achieved. Sex is a powerful force, and not everyone is minded to reserve sexual activity for that "special one." In our sex-saturated society, sex has so often been reduced to it's animal roots, and the love and devotion that should be part of it is often ignored. But sex, properly practiced, can be ennobled and raised to a high spiritual activity—the natural outcome of devoted love for another and for the resulting offspring.
As for sex outside of marriage, I cannot judge whether it is "bad" for you or not. This would require my knowing a lot more about your motives and goals, and is a subject that you can only decide for yourself. In primitive times, it was not thought of as anything out of the ordinary...but in my lifetime, sex outside of marriage was considered a major taboo. Now, the pendulum has swung again to a more liberal view of sex. But this does not mean that sex should be treated lightly. Sexual promiscuity can be very damaging to one's spiritual growth, as it can foster a selfish attitude towards others. Again, motive is very important when assessing the morality of sex outside of marriage, and is something that only you (and your partner) can determine for yourselves.
I would invite you to read carefully the section on the mating instinct HERE
, and use your highest thinking when interpreting the information you read. You would be well-served to read that entire paper (The Evolution of Marriage) while you're at it.
As for monogamy, here are some clear Urantia Book teachings on the subject:
83:6.6 Monogamy always has been, now is, and forever will be the idealistic goal of human sex evolution. This ideal of true pair marriage entails self-denial, and therefore does it so often fail just because one or both of the contracting parties are deficient in that acme of all human virtues, rugged self-control.
Monogamy is the yardstick which measures the advance of social civilization as distinguished from purely biologic evolution. Monogamy is not necessarily biologic or natural, but it is indispensable to the immediate maintenance and further development of social civilization. It contributes to a delicacy of sentiment, a refinement of moral character, and a spiritual growth which are utterly impossible in polygamy. A woman never can become an ideal mother when she is all the while compelled to engage in rivalry for her husband’s affections.
Pair marriage favors and fosters that intimate understanding and effective co-operation which is best for parental happiness, child welfare, and social efficiency. Marriage, which began in crude coercion, is gradually evolving into a magnificent institution of self-culture, self-control, self-expression, and self-perpetuation.
Thanks for sending us this great question. I hope that this reply has been helpful to you."