You know the idea that there are angels sitting on our shoulders, one good and one bad, each making its case in the attempt to convince us to do their bidding? Well, it's true, though they are not angels.
The poet Rumi entitled an entire volume of poems "We Are Three". That three consists of:
1) The physical body.
2) The soul.
3) The spirit.
The free will (connected with the mind) is unique to the human race. It is what separates us from the animals in that we get to choose what to do (animals are simply compelled by necessity/opportunity). What the free will commands is the first body: the physical body. The free will uses the mind to choose between the options given it from the soul and the spirit.
The spirit is of divine origin and relays commands to us that will lead not only to our own personal happiness, but to the happiness of the people around us. Its source is the Divine Will and it is incapable of relaying any negative suggestion to us.
The soul is capable of relaying both vice and virtue. At first, in *all* human beings, the soul is tuned to relay only the commands that will lead us away from happiness. "As you sow, so shall you reap" is quite true, and, in order to create unhappiness in us, the soul relays commands that create unhappiness for others, through the 19 different vices (such as anger, hatred, enmity, rebellion, assumption, ignorance, addiction, impatience, overbearance). When a human being chooses to act upon the soul's negative suggestions, it creates unhappiness for others and, subsequently through the Law of Karma, for themself.
Within our Creator's grand design there is a process that a human being can (and should!) go through to replace all the vices in the soul with their corresponding virtue (e.g. replacing hatred with love). This is called "cleansing the soul" in Sufi parlance and leads, if successfully completed, to the soul also relaying only the Divine Will.
At that point, all strife has ended for the person because, for one, there is no more conflict between the commands coming from the spirit and soul, and, two, all the Divine commands only lead to happiness. When Jesus said "I and the Father are one", this is exactly what he was referring to; namely, that he was completly harmonized with the Divine Will.
The most important piece of information related to this *most* important of all human endeavors is this: to begin the process of soul cleansing, one must make the following wish/prayer:
"Lord/God/Allah/Jehovah/..., please take my spirit into Yourself in my lifetime that I will do your Divine Will."
Once this wish to reach God is made from deep within your heart, your very being undergoes certain changes. As well, you begin the journey to submission to the Divine Will, which is the road to happiness, for one's self and for everyone around you.
May all the peace, prosperity and happiness of this world and the next be with you and our entire human family.
More later, insha'Allah.