In Christian theology, "nature" is simply the faithful rule of God over everything in the creation.
"We must not take nature too seriously, in place of God, nor may we treat nature with less seriousness than as the creation of God. To enjoy this proper harmony between man and the world we need 'theocracy', God's rule in the world. This is the meaning of the landscape of creation: that God is King. This affirmation alone enables man to live in an authentically open world, open to the nature and needs of man as a person. For the rule of God implies the intersection of earth and heaven, time and eternity, human responsibility and divine grace."James Houston, I Believe in the Creator, p. 44).
God is self-sufficient and free. There is nothing higher than God that determines what happens. If that were the case, then that would be God, by definition. Also, there is no chance back of God. God wills and it is done.
This does not mean that God can do absolutely anything. For instance; God cannot create a stone too heavy for Him to lift. That is irrational. God cannot contradict Himself. God cannot disobey his own moral character.
God did not need to create. In particular, God did not create mankind because He was lonely. Love and "I-Thou" personal relationships were eternally existent in the Godhead, because God is a Trinity consisting of three Persons.