Leibniz’s philosophy and his concept of God are influenced by the Christian philosophy and theology, and the Spinozism and Cartesian philosophies. Leibniz was also influenced by some Platonic dialogues. But Leibniz theological status is more voluble than Descartes and Spinoza, and his philosophy is theocentric like Malebranche philosophy. Final cause and efficient cause in Leibniz opinion are in line with God’s causality. Consequently with this idea Leibniz becomes close to the principle of “there is no cause except God”. Leibniz uses pre-established harmony and believes that mechanical cause is under the domination of the final cause. Leibniz criticizes Descartes concept of God strongly and in his view the Cartesian God is Similar to Spinoza’s God, the God who is omnipotent, Primary Nature, and lacks any will and understanding. The Cartesian perfect being is not the God, whom we imagine; who is the wise and just God; who does everything for the good of his creatures. The artificial God – like Descartes one – leaves us no option, but to accept obligation through patience. Spinoza denies any concept and definition of God as a wise and willing being. In his opinion God does not act through free will. The relation of wisdom and will to God is similar to the relation of movement and inertia. Therefore, the world has a mathematical and mechanical system and essentially is not ethical, humane, or rational. Everything occurs because of objective and un-reflexive rules of cause and effect. Leibniz strongly criticizes Spinoza’s concept of God and says: God is a definitive substance, person, and mind, but at the same time is the most perfect substance, God is the Monad of Monads, who harmonizes Monads activities through using his decisive mathematical order. Finally Leibniz introduces one nature – a simple substance or the Monad of Monads – as a transcendental being – or God -, the God who through ethical necessity should create the best possible world. Has Leibniz ultimately reached a philosophy - Spinozism - which he before denied strongly? What is the difference between ethical necessity in Leibniz philosophy and Spinoza’s natural necessity? This article aims to Explain Leibniz theology. Many new points exist in Leibniz theological approaches, which have been clouded by the excessive attention paid to Descartes philosophy in Iran’s philosophical sites. Also it wants to compare some of Leibniz’s theological views with the views presented by Plato, Aristotle, Descartes, Malebranche, and Spinoza. And finally, this paper aims to criticize Leibniz theology from certain viewpoints according to the capacity of this article.