The time he lived, his education, and having been a professor of moral philosophy at the University of Glasgow in the 18th century seemingly might suggest this; however, scholars have different views.
I would submit the following comments (tentative answers) to your questions:
1. Smith was assuredly not "religious" in the usual sense of the term. To my mind, the time he lived, during the Scottish Enlightenment, actually suggests a likelihood that he was not that religious. (His good friend David Hume openly scoffed at religious beliefs and authority, but that could still get you in trouble.)
2. The "Invisible Hand" that guided Smith's market might suggest a religious sensibility, but I think that interpretation is mistaken. It's not that there _is_ an invisible hand guiding the market, but that it's _as though_ such a hand existed. The astonishing reality, Smith is saying, is that complex order can seemingly emerge from human (conscious) acts that have no intention with respect to that order. The social order is an unintended by-product of the acts and choices of individuals. Note that the other interpretation, that "the invisible hand" is a higher consciousness of some kind, is easily understandable. Consider an industrial assembly line where automobiles are produced: The workers on the line don't know how to produce a car, even though they are, collectively, doing just that. How can that be? Well, engineers who _do_ know how to produce a car have designed a complex system that gives each worker a task; taken together, the performance of these tasks works the will of the Designer(s). Surely it's the same with an economy that produces what we need to live and thrive? --But no, that rich, complex order happens _as though_ designed, but it's not designed.
3. "Religious views," then, undoubtedly influenced his work, but in the opposite way we might tend to suppose. In Smith's time, and especially in the United Kingdom, "natural philosophy" was mightily in vogue. Scientists (not so called yet) were avidly seeking natural causes and accounts of reality. Mostly, as far as I can see, they looked at "nature" in the obvious sense (physical bodies, observable phenomena), but some, like Hume and Smith, looked at institutions and patterns of behavior and tried to account for these as empirical phenomena. This methodological style might be thought of as a reaction to the theological approach, and in that sense, was influenced by religion.
Adam Smith's system is named as "the System of Moral Philosophy" and is composed of four parts. The first part is "the natural deism". The second part is "Moral Sentiment
or Ethics". The third part is "Jurisprudence". The fourth part is "Political Economy".
He published "The theory of moral sentiments" (1758)and " The Wealth of Nations"(1776) .But he could not published the books on theology and jurisprudence.He was influenced by Scottish Enlightenment. Perhaps he had the same thought on religion
Even if each man seeks his own interest on economic activities, the division of labor can develop and the wealth of society can grow from these egoistic activities of economic men. Adam Smith thought so. And this result can be realized by invisible hand of the God. So the precondition of Smith's economic system is the existence of the God.
I think the theories and analysis proposed by Adam Smith were against the moral ethics that each and every religious philosophy preached. Although his own life was influenced by activities around religious institutions his economic thoughts were hardly linked with religion or religious ethics. Not even the concept of "invisible hand'.
I think your question throws a wrench into positive economics. Neither can normative economics be alienated from religion. Economics as conceived by Adam Smith was not a dichotomous discipline. It was interpreters of his works, sadly economists, that sought to see it that way as a convenient, enlightened truth. If one needs to be moral in order to be religious, then the answer to the question is:yes and no. Yes in the sense that the 'theory of moral sentiments' (TMS) was not a pure work of behavioral economics neither was it purely theology.Adam Smith strikes me as a figure that is seminal in the same way as Beethoven was to Western music. Both men appeared on the scene at the cusp of a transition. The TMS was "the religion of economics". While the Wealth of Nations (TWON) became "the manifesto of economics". Nevertheless the use of the word "moral" has puzzled many. Arguably some have credited him for promoting selfishness after reading his ideas about laissez-faire. But I believe the morality/religion of economics has to do with"means-ends". The "ends" or the emergence of economic coordination, which I think is central to Smith's work, is explained in terms of its "means"- the self- interest of the market participants. "No" to the question (he was not religious) in the sense that, ironically,the morality of the market hinges on the indifference towards morality. Just as it would not be morally sound to discourage personal savings, it would nonetheless be detrimental to the economy as a whole if most people held to personal savings as a moral obligation, ceteris paribus (the idea and reasoning supporting the multiplier effect.).
Wish to reinforce my statement: "I think your question throws a wrench into positive economics. Neither can normative economics be alienated from religion. Economics as conceived by Adam Smith was not a dichotomous discipline. It was interpreters of his works, sadly economists, that sought to see it that way as a convenient, enlightened truth. "
The link above provided by Shian-Loong Bernard Lew references a paper by John B. Davis entitled: Economists’ Odd Stand on the Positive-Normative Distinction: A Behavioral Economics View. It is interesting and goes far deeper and wider than my original question, especially in its historical coverage. The origins of the positive-normative distinction along with ideas about applicability to current areas of economics is fascinating.
I would submit the following comments (tentative answers) to your questions:
1. Smith was assuredly not "religious" in the usual sense of the term. To my mind, the time he lived, during the Scottish Enlightenment, actually suggests a likelihood that he was not that religious. (His good friend David Hume openly scoffed at religious beliefs and authority, but that could still get you in trouble.)
2. The "Invisible Hand" that guided Smith's market might suggest a religious sensibility, but I think that interpretation is mistaken. It's not that there _is_ an invisible hand guiding the market, but that it's _as though_ such a hand existed. The astonishing reality, Smith is saying, is that complex order can seemingly emerge from human (conscious) acts that have no intention with respect to that order. The social order is an unintended by-product of the acts and choices of individuals. Note that the other interpretation, that "the invisible hand" is a higher consciousness of some kind, is easily understandable. Consider an industrial assembly line where automobiles are produced: The workers on the line don't know how to produce a car, even though they are, collectively, doing just that. How can that be? Well, engineers who _do_ know how to produce a car have designed a complex system that gives each worker a task; taken together, the performance of these tasks works the will of the Designer(s). Surely it's the same with an economy that produces what we need to live and thrive? --But no, that rich, complex order happens _as though_ designed, but it's not designed.
3. "Religious views," then, undoubtedly influenced his work, but in the opposite way we might tend to suppose. In Smith's time, and especially in the United Kingdom, "natural philosophy" was mightily in vogue. Scientists (not so called yet) were avidly seeking natural causes and accounts of reality. Mostly, as far as I can see, they looked at "nature" in the obvious sense (physical bodies, observable phenomena), but some, like Hume and Smith, looked at institutions and patterns of behavior and tried to account for these as empirical phenomena. This methodological style might be thought of as a reaction to the theological approach, and in that sense, was influenced by religion.
I don't think we will ever know if Smith himself was religious; however, there is substantial evidence to believe he was **very** influenced by the religious views of his time. Smith's thought was influenced by the Protestant natural law tradition, beginning with Grotius and Pufendorf and pass on through Gershom Carmichael and Francis Hutcheson. While Jacob Viner's 1926 article "Adam Smith and Laissez-Faire" challenged the belief of a strong connection between TMS and WN, which was interpreted by later economists as challenging the idea of any connection between the two works. There is a new perspective (the "new theistic perspective") which is challenging the view of Viner's 1926 article on the basis of Viner's revised view in his later writings.
In addition to Viner's The Role of Providence in the Social Order and Essays in the Intellectual History of Economics, I suggest McRorie's article "Adam Smith, Ethicist" and J.E. Alvey's "The Secret, Natural, Theological Foundation of Adam Smith's Work".
Smith is not a religious person, may be that all Scottish enlightened people are not religious, Hume was the most representative of this position. It may be in the eighteenth century, the Scottish teachers were fracmasons or rosicrucians, as was common to English and French intellectuals. I also think that possibly there should have been many Deists at that time. Now with respect to the Invisible Hand, this is neither a mistaken religious vision, nor an expression of the possible religiosity of Smith. It is the theory of the unintended consequences of the scholastics, which I think was a common theme of the Scots and other Englishmen who were in search of natural laws, as at the time the late Spanish scholastics did.