This is my take on why we came down into the world:
Before we were born we were souls enjoying paradise. Paradise is perfect. Everyone is so well taken care of that there are probably no needy souls. The Creator nourishes all the souls with all the spiritual lights they desire. The souls are given everything, except for the very ability to give. Yet, even though paradise does not offer souls with meaningful opportunities to give, giving is not unknown to them. The souls are aware of giving because of the nurturing care being given to them by the Creator. In fact, implanted within the nurturing lights they receive, are traces of their Creator's desire to give. Like a suckling ingesting traces of his/her mother's love, souls ingest traces of the Creator's desire to give - filling them with a yearning to give as well.
Besides, the way their Creator's desire to give becomes part of their fabric, there's yet another source for their passion to give. Like any child, they want to imitate their Divine Daddy. By souls striving to resemble their Creator's behavior, they feel closer to Him. In the spiritual realms, space is defined by similarity and dissimilarity. What dissimilar is farther away. What's similar is closer. By imitating the Creator's ways, they become more similar to Him, i.e. closer to Him.
As a compassionate favor, the Creator sent us earthward, down into the physical realm, where there is plenty of need; hence, also plenty of opportunities to “give”! Next time you face human suffering and you wonder why? Just ask yourself, "What would I expect a place where there are plenty of opportunities to give to look like?"
Each soul is given a body along with a set of resources, a special tool kit for giving. Often what looks like the gifts the Creator had intended to give to us, are really the gifts the Creator intended to give through us. He also, gave each of us areas of weakness and vulnerability, so we can serve as an opportunity for other souls to give as well. What others need we give. What we need others give. This way the physical realm can serve as an opportunity to allow all souls their passion to give.
Yet, to allow for this opportunity to give, to give again and again, the soul needs a body. There's just no other way for the soul to reach down into planet earth and participate in the sweetness of giving. One needs shoes to walk the rough streets of the world. The body is the soul's shoe. Fortunate, is the soul who is privileged to enjoy the company of his/her soul-mate. That soul walks with two legs in two shoes - far more balanced than those who have to hop along in one shoe. Even if another hopping shoe joins the hopper, its just not the same. It belongs to a different being. Coordination is not as smooth.
With the awareness that the body is the means for the soul to reach into the physical realm and disseminate kindness, a person should try his/her best to take good care of his/her health. The body is truly a special and precious partner on the soul's journey. The healthier the body, the more giving the soul will be able to perform; as she finds her body a sturdy and comfortable shoe for a very long walk ahead ... in dissemination of kindness.