The explicitly "Quaker" evidence for this facet of this proposed "testimony" may be weaker than some other facets. Certainly there has not been any strong explicit Quaker tradition of dualism or rejection of the body. The Testimony on Integrity upholds the basic principle that all areas of life are the stuff of spirituality. All that we live must be an expression of faithfulness.
Both George Fox and John Woolman expressed a strong belief that the natural creation was itself an expression of God's work. Fox wrote about all creation "taking on a new smell." Woolman was concerned about the ways in which wrong use of possessions would be harmful to the earth and to animals. If the creation is a central part of God's plan, why not also our bodies?
#4 Sexual Acts as Expressions of Love
God wants us to utilize the act of physical lovemaking as the outward expression of emotional and spiritual intimacy with the person we are touching physically.
How does God feel about casual sex among singles, or, for that matter, between married partners? Our society glorifies casual sex. Films often focus on sex in the context of falling in love, but how often do they celebrate sexuality within the context of long-term committed love? Sex for its own sake is promoted constantly in advertising. It is hard not to be influenced by the constant barrage of messages encouraging us to look at and long for young, healthy, stereotypically "attractive" bodies.
What does it mean, however, to touch another person where there is not love, or where the sexual act is an expression of physical need rather than spiritual intimacy? Is casual sex a form of hard-heartedness? Does it involve a certain closing off of one's heart in the act of physical intimacy? It would seem to involve focusing on one's own physical pleasure while not truly embracing the spirit of the person one is with. This also applies to looking at persons and images in a sexual manner without a sense of respect and caring, in effect as a consumer of another person's sexual attractiveness.
The word "incarnation" means literally "becoming flesh." When we love another person deeply, our hearts touch each other. When this spiritual closeness is expressed by physical touching, it becomes embodied, "en-fleshed." Physical touching does not have to mean sex, of course. Physical affection can reflect spiritual connection in the affectionate hug or touch between those who feel spiritually connected. A special kind of spiritual and emotional closeness can also, though, grow into sexual expression. There is power in limiting sexual closeness to a relationship in which there is great emotional and spiritual intimacy.
Again, I have less clear evidence that Quakerism has a strong position on this issue historically than some other questions. Some evidence for this would include the following:
1) The Testimony on Simplicity (the one I often like to call the Testimony on Purity) is about living a way of life that makes it more possible for us to hear and obey God's voice in our hearts. Belongings, addictions, clutter, excessive activity can all interfere with our ability to experience the touch of the "still small voice."
Open-heartedness in one area nurtures open-heartedness in other areas. It has been observed that sexual passion and spiritual passion are deeply connected. When we open our hearts courageously to another person in sexual intimacy, we open doors in our hearts to God. Similarly, when we practice sexuality while closing our hearts to the person we are touching physically -- or looking at -- we may also close our hearts to God.
2) The First Epistle of John teaches us that we cannot love God without loving those near us. That God is something we do not see, and we experience love of God when we love the humans we are in contact with.
3) As mentioned earlier, Jesus appears to believe that nurturing caring feelings toward others and avoiding "lustful" or unloving possessive desires is an important part of faithfulness. The Epistle to James also suggests that feelings of "lust" or longing to possess others' things (including their bodies for our own pleasure?) is associated with conflict and war. This passage was at the heart of early Friends' opposition to war.
4) Fox wrote a number of epistles about sexuality. It involved his debate with his Puritan opponents on the issue of perfectionism. The Puritans argued that no one other than God or Jesus could attain a life of perfection. Fox attacked this idea as "apology for sin." He argued that one who found complete freedom in Christ was able to live free from sin. These ideas are hard to grasp today!
He went on to suggest that those who argued for sin condemned sexual love between married partners to be expressions of "animal lust." I do not fully understand what Fox was getting at in these writings (which he returned to on a number of occasions), but I believe he was arguing for the basic purity of sexual expression as being possible for those who developed a truly committed relationship with the Living Christ in the context of a faithful community.