Deism is the combination of the intuition of the transcendence of God and the belief that God cannot, or, at least, does not, interact with, nor otherwise involve Himself in, the Creation. Deism is contrasted with pantheism, in that pantheism is the combination of belief in an omnipresent Creator God and the belief that God's omnipresence implies that God is the Creation.
In its mildest form, Deism is nearly equivalent to a belief that no one can truly know whether there is a God or not (agnosticism). In its strongest form, Deism is a systematic religion of rejecting all claims to a personal, or otherwise involved, God, in that God is supposed incapable, by His transcendence, of any kind of interaction with the Creation.
In its typical modern form, deism is anti-Christian, as it denies the divinity of Jesus Christ, rejects the Bible (and all other texts) as God's scripture, and denies his signs and miracles to men. It lacks any coherent morality, and is an excuse to claim to be religious while engaging in immoral activity. Thus it is a favorite of liberals who do not want to be branded with atheism.
Deism is also only a short step away from atheism, and deistic beliefs often create a slippery slope to atheism[Citation Needed]. This is a common tactic of atheist evangelists: first convince a Christian that God has left the world alone, and then deny the necessity of God. Atheism and Deism are, for the most part, morally and cosmologically equivalent, given God's presumed inaction of any moral and cosmological revelation, an exception being that Atheism more easily permits worship of man by man while Deism holds that God is greater than man.
In ancient times, Aristotle was a deist as is evident from his arguments for a prime mover in his writing, Metaphysics. Even though the word deism was not yet coined, he still believed what deists believe: that God exists and is knowable through natural reason. 
The founder of the offshoot of that found a place in England during the Reformation and reached the colonies was Lord Herbert of Cherbury.  He came up with 5 essentials of Deism which are "(1) a belief in the existence of the Deity, (2) the obligation to reverence such a power, (3) the identification of worship with practical morality, (4) the obligation to repent of sin and to abandon it, and, (5) divine recompense in this world and the next". This was a rather odd variant mixing in many Christian virtues without Jesus, and rather foreign to traditional Deism.
Dictionaries' definitions of deism include:
- The belief, based solely on reason, in a
- "a movement or system of thought advocating natural religion, emphasizing morality, and in the 18th century denying the interference of the Creator with the laws of the universe."
The first definition refers to a conception of God sometimes called the deus otiosus.
The Catholic Church would denounce Deism as a Heresy in the 1500s, for its rejection of the divinity of Jesus Christ, the importance of the church, and eschewing the idea of Divine Intervention. While Lord Herbert would found the movement, by the 1800s his arguments were largely demolished by the philosopher Locke and his deconstruction of the concept of an 'Innate Truth'(Upon which much of Herbert's views on Deism were founded).
Matthew Tindal is generally credited with the modern incarnation of Deism and that practiced by the Founding Fathers who were Deists. "God designed all Mankind should at all times know, what he wills them to know, believe, profess, and practice; and has given them no other Means for this, but the Use of Reason."
Deism would enjoy a brief rise in the Western world through the 1800s, but by the early 20th century, it was on the decline. The Unitarian movement would absorb most of its teachings and eventually produce the Unitarian Universalists. Deism today is a mixed bag without dogma or teachings beyond the idea that one should employ Reason to understand the universe. As a result, Deists who believe in Divine Intervention, Intelligent Design, and many other ideas that would have been alien to the earlier Deists are now around.
Deism and the Founding Fathers
While almost all of the Founding Fathers were devout Christians[Citation Needed], some it is believed were deists, at least according to some definitions of the term.
A famous deist in early American history was the Englishman Thomas Paine, who espoused deism and popularized the term in his book The Age of Reason. It is believed this had an influence on deism in the colonies. Benjamin Franklin wrote in his autobiography about an earlier period in his life,
Some books against Deism fell into my hands; they were said to be the substance of sermons preached at Boyle's Lectures. It happened that they wrought an effect on me quite contrary to what was intended by them; for the arguments of the Deists, which were quoted to be refuted, appeared to me much stronger than the refutations; in short, I soon became a thorough Deist.
FranklinFranklin later repudiated many of his earlier views and he believed in a God that "ought to be worshiped," and at the Constitutional Convention less than three years from his death Benjamin Franklin advocated public prayer. He praised Christianity, but his letter to Ezra Stiles a month before his death was noncommittal as to the divinity of Jesus:
"As to Jesus of Nazareth, my opinion of whom you particularly desire, I think the system of Morals and His Religion as he left them to us, is the best the world ever saw, or is likely to see.. I have, with most of the present Dissenters in England, some doubt as to his Divinity; tho' it is a question I need not dogmatize upon, having never studied it, and think it needless to busy myself with it now, when I expect Soon an opportunity of knowing the Truth with less trouble. I see no harm in its being believed, if that belief has good consequences, as probably it has, of making his Doctrines more respected and better observed."
The leading Founder of the United States, George Washington, has been claimed as a deist during the past forty years, despite written evidence to the contrary, both in Washington's writings as well as the writings of his contemporaries. An Episcopalian, Washington rented church pews in various cities and acted as usher; the pew Washington rented at St. Paul's Chapel in New York City is still preserved. The tenents of his church during the 18th and 19th centuries were such that outward displays of piety and religiosity were avoided, in keeping with the Christian practice of Matthew 6:5: "And when thou prayest, thou shalt not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward." (King James Version). Anglican manners seek a "middle ground", which for all intents and purposes was a path that would find the least devisiveness, to avoid or give offense, to keep the peace, and yet to keep space open for shared ideas. The rules for a "gentleman" stated that a "devout" man kept his devotion restrained in public; Washington himself was described by witnesses and biographers as such a man, one who kept his religion and beliefs private.
But when Washington did speak of religion and his faith, he strongly indicated which faith he was talking about. In May, 1789, he sent a letter to the General Assembly of Presbyterian Churches:
- "While I reiterate the professions of my dependence upon Heaven as the source of all public and private blessings; I will observe that the general prevalence of piety; philanthropy, honesty, industry, and economy seems, in the ordinary course of human affairs, particularly necessary for advancing and conforming the happiness of our country. While all men within our territories and protected in worshipping the Deity according to the dictates of their consciences; it is rationally to be expected from them in return, that they will be emulous of evincing the sanctity of their professions by the innocence of their lives and the beneficence of their actions; for no man, who is profligate in his morals, or a bad member of the civil community, can possibly be a true Christian, or a credit to his own religious society."
- "Brothers: I am glad you have brought three of the Children of your principal Chiefs to be educated with us. I am sure Congress will open the Arms of love to them, and will look upon them as their own Children, and will have them educated accordingly. This is a great mark of your confidence and of your desire to preserve the friendship between the Two Nations to the end of time, and to become One people with your Brethren of the United States. My ears hear with pleasure the other matters you mention. Congress will be glad to hear them too. You do well to wish to learn our arts and ways of life, and above all, the religion of Jesus Christ. These will make you a greater and happier people than you are. Congress will do every thing they can to assist you in this wise intention; and to tie the knot of friendship and union so fast, that nothing shall ever be able to loose it."
- "Washington cannot be called a Deist — at least, not in a sense that excludes his being Christian. Although he did most often address God in the proper names a Deist might use — such as "Author of all the good that was, that is, or that will be" and "Disposer of all human events" — the actions that Washington expected God to perform, as expressed both in his official public prayers (whether as general or as president) and in his private prayers as recorded, are the sorts of actions only the God of the Bible performs: interposing his actions in human events, forgiving sins, enlightening minds, bringing good harvests, intervening on behalf of one party in a struggle between good and evil (in this case, between liberty and the deprivation of liberty), etc." 
Modernly, as noted above, Deism has both declined and fractured, with some of its original ideas being adopted as part of "new age" movements. Variations of Deism that have developed or been proposed include Pandeism (enunciated in the 1850s, and merging Deism with Pantheism, the idea that God is equal to the Universe); Polydeism (merging Deism with polytheism, proposing that multiple Gods created then abandoned the Universe); and Panendeism (merging Deism with the 1830s idea of Panentheism, that the Universe was part of God, but was also transcended by God). None of these offshoots has garnered a significant following relative to organized religions, although it should be noted that many strains of Hinduism are in fact Pandeism.
Though many claim deism is Christian, today's deism as it stands is squarely anti-Christian; it denies the involvement of God in human affairs, removes Him from a personal relationship with individuals, and leaves unanswered the question of sin. In the Book of Revelation, Jesus clearly gives an answer to such a "half-in, half-out" philosophy:
- And unto the angel of the church of the Laodiceans write; These things saith the Amen, the faithful and true witness, the beginning of the creation of God;
- I know thy works, that thou art neither cold nor hot: I would thou wert cold or hot.
- So then because thou art lukewarm, and neither cold nor hot, I will spue thee out of my mouth.
- Because thou sayest, I am rich, and increased with goods, and have need of nothing; and knowest not that thou art wretched, and miserable, and poor, and blind, and naked:
- I counsel thee to buy of me gold tried in the fire, that thou mayest be rich; and white raiment, that thou mayest be clothed, and that the shame of thy nakedness do not appear; and anoint thine eyes with eyesalve, that thou mayest see. (Revelation, Ch. 3:14-18, KJV)
- Merriam-Webster online: deism
- Novak, pg 12
- Novak, pg. 12
- Washington, George. Writings; Library of America, New York (1997)
- Novak, Michael, and Novak, Jana. Washington's God: Religion, Liberty, and the Father of Our Country; Basic Books, New York (2006)
- An Account of the Growth of Deism in England by William Stephens.
- America's God: From Jonathan Edwards to Abraham Lincoln, Mark A. Noll, 3rd Ed.,Oxford University Press, 2002, ISBN 0195151119, 9780195151114