What is Unitarian?Unitarianism can be viewed as a form of Nontrinitarianism which is a form of Christianity that rejects the mainstream Christian doctrine of the Trinity. The teaching that God is three distinct hypostases or persons who are coeternal, coequal, and indivisibly united in one being, or essence (from the Greek ousia). Certain religious groups that emerged during the Protestant Reformation have historically been known as antitrinitarian, but are not considered Protestant in popular discourse due to their nontrinitarian nature. According to churches that consider the decisions of ecumenical councils final, Trinitarianism was definitively declared to be Christian doctrine at the 4th-century ecumenical councils, that of the First Council of Nicaea (325 AD), which declared the full divinity of the Son, and the First Council of Constantinople (381 AD), which declared the divinity of the Holy Spirit. In terms of number of adherents, nontrinitarian denominations comprise a minority of modern Christianity. The largest nontrinitarian Christian denominations are The Church of Jesus Christ of Latter-day Saints ("Mormons") and Jehovah's Witnesses.
What is Buddhism?Buddhism is the world's fourth-largest religion with over 520 million followers, or over 7% of the global population, known as Buddhists. An Indian religion, Buddhism encompasses a variety of traditions, beliefs and spiritual practices largely based on original teachings attributed to the Buddha and resulting interpreted philosophies. Buddhism originated in Ancient India as a Sramana tradition sometime between the 6th and 4th centuries BCE, spreading through much of Asia. All Buddhist traditions share the goal of overcoming suffering and the cycle of death & rebirth, either by the attainment of Nirvana or through the path of Buddhahood.
What is Atheism?Atheism is, in the broadest sense, the absence of belief in the existence of deities. Less broadly, atheism is the rejection of belief that any deities exist. In an even narrower sense, atheism is specifically the position that there are no deities. Atheism is contrasted with theism, which, in its most general form, is the belief that at least one deity exists.