The Christian and biblical doctrine of the Trinity asserts the following:
- There is one and only one God (monotheism)
- There are three distinct persons: Father, Son, and Holy Spirit
- Each person is fully and completely divine, each sharing the same substance
- The persons are not to be confused with one another - the Father is not the Son, the Son is not the Holy Spirit, etc.
Since its inception, Mormonism teaches that the Father, Son, and Holy Spirit are distinct beings and therefore separate Gods. This view stems from Joseph Smith's experience of the Father and Son, both having their own separate bodies. In short, Mormons are tritheists (i.e. belief in three Gods). Many LDS use the terms "being" and "person" interchangeably. Therefore, Mormons can affirm "three persons" but this is also flexible enough to mean "three beings." LDS may also agree that there is one God, but this really means one "Godhead" in which three beings - Father, Son, and Holy Spirit - exist in one unified purpose and power but not substance or essence (i.e. no ontological unity).
One common reason LDS reject the Trinity is that the word itself is not found in the Bible. However, neither can such words as "eternal progression" and "divine investiture". It is reasonable and acceptable to use extra-biblical words to describe biblical concepts, and the concept of the Trinity itself was developed from the biblical doctrines of the oneness of the being of God (monotheism) and the plurality of the persons within this one being. Roger Olson reminds us that "Christian belief in God as triune did not arise in the fourth century with Roman emporer Constantine and the Christian bishops that he dominated. Belief that it arose then as part of a vague paganizing or Hellenizing of Christianity is a caricature often promoted by anti-trinitarian cults and sects" (Roger Olson, The Mosaic of Christian Belief, p. 135).
 Mormonism and Social Trinitarianism
Some Mormons, specifically David Paulsen and Blake Ostler, have been dealing with the idea of Social Trinitarianism. This idea understands the plurality of persons as a community, each of which share in the essence - the very nature - of what it is to be God. Those in the west have been uncomfortable with this viewpoint fearing that it will result in a similar understanding of polytheism.
 See also
- Mormonism 201: Chapter 3 The Trinity, Response to René Alexander Krywult by John Divito
- The Polytheistic Trinity of Mormonism (Concerned Christians)
- How do I explain the Trinity to my Mormon friend? (Concerned Christians)
- Gregory of Nyssa and the Social Analogy of the Trinity, by Cornelius Plantinga, Jr.
- Toward a Biblical Model of the Social Trinity: Avoiding Equivocation of Nature and Order (pdf), by J. Scott Horrell (JETS)
- The Doctrinal Exclusion: Trinity and the Nature of God, by Stephen E. Robinson
- Do Mormons believe in the concept of the Holy Trinity?
- Does the Book of Mormon teach Mainstream Trinitarianism or Modalism?, by Barry Bickmore (FAIR)
- Are Mormons Trinitarian? - An Interview with Dr. David Paulsen