The main difference between Deism and Theism is that the Deism is a belief in God without revelation or authority and Theism is a belief in the existence of at least one deity.
Deism ( DEE-iz-əm or DAY-iz-əm; derived from Latin “deus” meaning “god”) is the philosophical position that rejects revelation as a source of religious knowledge and asserts that reason and observation of the natural world are sufficient to establish the existence of a Supreme Being or creator of the universe.At least as far back as Thomas Aquinas, Christian thought has recognized two sources of knowledge of God: revelation and “natural reason”. The study of the truths revealed by reason is called natural theology. During the Age of Enlightenment, especially in Britain and France, philosophers began to reject revelation as a source of knowledge and to appeal only to truths that they felt could be established by reason alone. Such philosophers were called “deists” and the philosophical position that they advocated is called “deism”.
Deism as a distinct intellectual movement declined toward the end of the 18th century. Some of its tenets continued to live on as part of other intellectual movements (e.g. Unitarianism) and it continues to have some advocates today.
Theism is broadly defined as the belief in the existence of a Supreme Being or deities. In common parlance, or when contrasted with deism, the term often describes the classical conception of God that is found in monotheism (also referred to as classical theism) – or gods found in polytheistic religions—a belief in God or in gods without the rejection of revelation as is characteristic of deism.Atheism is commonly understood as rejection of theism in the broadest sense of theism, i.e. the rejection of belief in God or gods. The claim that the existence of any deity is unknown or unknowable is agnosticism.
A philosophical belief in the existence of a god (or goddess) knowable through human reason; especially, a belief in a creator god unaccompanied by any belief in supernatural phenomena or specific religious doctrines.
Belief in a god who does not intervene with existence.
Belief in the existence of at least one deity.
Belief in the existence of a personal creator god, goddess, gods and/or goddesses present and active in the governance and organization of the world and the universe. The God may be known by or through revelation.
A morbid condition resulting from excessive consumption of tea.