Monergism

God is self-existent, God has always been...Our Maker exists in an eternal, self-sustaining, necessary way, ­necessary, that is, in the sense that God does not have it in Him to go out of existence, just as we do not have it in us to live forever. We necessarily age and die, because it is our present nature to do that; God necessarily continues forever unchanged, because it is His eternal nature to do that. This is one of many contrasts between creature and Creator...God's self existence is basic truth. At the outset of his presentation of the unknown God to theAthenian idolaters, Paul explained that this God, the world's Creator, "is not served by human hands, as if he needed anything, because he himself gives all men life and breath and everything else"� (Acts 17:23-25). Sacrifices offered to idols, in today's tribal religions as in ancient Athens, are thought of as somehow keeping the god going, but the Creator (the I AM) needs no such support system. The word aseity, meaning that he has life in himself and draws his unending energy from Himself (a se in Latin means "from himself"�), was coined by theologians to express this truth, which the Bible makes clear.
J.I. Packer Concise Theology pg. 26-7