Abandonment is a most excellent way of finding peace and happiness. That is desiring God's will and whatever He wills. To understand this better consider marriage vows that two people make. "I will love you for richer or poorer, in sickness and in health, until death do us part."
Circumstances arise in our lives that can be uncontrollable. Like when a loved one is diagnosed with a disease, suffers, and may even die. Or when someone loses their job due to recession or corporate downsizing. Abandonment means whatever happens--even when things seem to go "wrong"--we receive as God's will, understanding He allows such things to happen to sanctify us.
In the book, Self-Abandonment to Divine Providence, Father J. P. de Caussade, S.J. wrote, "To all there is but one answer--that the will of God is the only thing necessary; therefore, what it does not grant must be useless."
St. Teresa of Avila said, "In this holy abandonment springs up that beautiful freedom of spirit which the perfect possess, and in which there is found all the happiness that can be desired in this life; for in fearing nothing, and seeking and desiring nothing of all things of the world, they possess all."