"[it is] God's absolute rule over and constant care for all his creation to his glory and the good of his people."
Jerry Bridges
In other words, if you know that God takes up everything, he takes every cell, every word, every decision, every disappointment, every loss, every phone call, every set back and every influence on us, whether its our upbringing or education, or whether its an injury that we'd received, or reward we've been given, a success, a disaster... it's all under control.
Nothing gets outside of His control and he works for it for his Glory and for the good of us.. and this brings us deep peace.