One of the 2 best English philosophers.  He produced a number of essays on religion, enough to be compiled into a book, available through Prometheus Press.  His short autobiography is a gem. 

IMPIOUS CONCEPTIONS OF THE DIVINE NATURE IN POPULAR RELIGIONS OF BOTH KINDS

      THE PRIMARY RELIGION OF MANKIND arises chiefly from an anxious fear of future events; and what ideas will naturally be entertained of invisible, unknown powers, while men lie under dismal apprehen­sions of any kind, may easily be conceived. Every image of vengeance, severity, cruelty, and malice must occur, and must augment the ghastli­ness and horror, which oppresses the amazed religionist. A panic having once seized the mind, the active fancy still farther multiplies the objects of terror; while that profound darkness, or, what is worse, that glimmering light, with which we are environed, represents the spectres of divinity under the most dreadful appearances imaginable. And no idea of perverse wickedness can be framed, which those terrified devo­tees do not readily, without scruple, apply to their deity.  This appears the natural state of religion, when surveyed in one light. But if we consider, on the other hand, that spirit of praise and eulogy, which necessarily has place in all religions, and which is the con­sequence of these very terrors, we must expect a quite contrary system of theology to prevail. Every virtue, every excellence, must be ascribed to the divinity, and no exaggeration will be deemed sufficient to reach those perfections, with which he is endowed. Whatever strains of pane­gyric can be invented, are immediately embraced, without consulting any arguments of phonomena: It is esteemed a sufficient confirmation of them, that they give us more magnificent ideas of the divine objects of our worship and adoration.

Here therefore is a kind of contradiction between the different prin­ciples of human nature, which enter into religion. Our natural terrors pre­sent the notion of a devilish and malicious deity: Our propensity to adu­lation leads us to acknowledge an excellent and divine. And the influence of these opposite principles are various, according to the different situa­tion of the human understanding....

But as men farther exalt their idea of their divinity; it is their notion of his power and knowledge only, not of his goodness, which is improved. On the contrary, in proportion to the supposed extent of his science and authority, their terrors naturally augment; while they hope that no secrecy can conceal them from his scrutiny, and that even the inmost recesses of their breast lie open before him. They must then be careful not to form expressly any sentiment of blame and dis­approbation. All must be applause, ravishment, extacy. And while their gloomy apprehensions make them ascribe to him measures of conduct, which, in human creatures, would be highly blamed, they must still affect to praise and admire that conduct in the object of their devotional addresses. Thus it may safely be affirmed, that popular religions are really, in the conception of their more vulgar votaries, a species of demonism; and the higher the deity is exalted in power and knowledge, the lower of course is he depressed in goodness and benevolence; what­ever epithets of praise may be bestowed on him by his amazed adorers. Among idolaters, the words may be false, and belie the secret opinion.  But among more exalted religionists, the opinion itself contracts a kind of falsehood, and belies the inward sentiment. The heart secretly detests such measures of cruel and implacable vengeance; but the judgment dares not but pronounce them perfect and adorable. And the additional misery of this inward struggle aggravates all the other terrors, by which these unhappy victims to superstition are for ever haunted.

Lucian’ observes that a young man, who reads the history of the gods in Homer or Hesiod, and finds their factions, wars, injustice, incest, adultery, and other immoralities so highly celebrated, is much surprised afterwards, when he comes into the world, to observe that punishments are by law inflicted on the same actions, which he had been taught to ascribe to superior beings. The contradiction is still per­haps stronger between the representations given us by some later reli­gions and our natural ideas of generosity, lenity, impartiality, and jus­tice; and in proportion to the multiplied terrors of these religions, the barbarous conceptions of the divinity are multiplied upon us. Nothing can preserve untainted the genuine principles of morals in our judg­ment of human conduct, but the absolute necessity of these principles to the existence of society. If common conception can indulge princes in a system of ethics, somewhat different from that which should regu­late private persons; how much more those superior beings, whose attributes, views, and nature are so totally unknown to us? Sunt superis sua jura.² The gods have maxims of justice peculiar to themselves.

BAD INFLUENCE OF POPULAR RELIGIONS ON MORALITY

Here I cannot forbear observing a fact, which may be worth the atten­tion of such as make human nature the object of their enquiry. It is cer­tain, that, in every religion, however sublime the verbal definition which it gives of its divinity, many of the votaries, perhaps the greatest number, will still seek the divine favor, not by virtue and good morals, which alone can be acceptable to a perfect being, but either by frivolous observances, by intemperate zeal, by rapturous extasies, or by the belief of mysterious and absurd opinions. The least part of the Sadder, as well as of the Pentateuch,³ consists in precepts of morality; and we may also be assured, that that part was always the least observed and regarded. When the old Romans were attacked with a pestilence, they never ascribed their sufferings to their vices, or dreamed of repentance and amendment. They never thought, that they were the general robbers of the world, whose ambition and avarice made desolate the earth, and reduced opulent nations to want and beggary. They only created a dic­tator, in order to drive a nail into a door; and by that means, they thought that they had sufficiently appeased their incensed deity.

In Aegina, one faction forming a conspiracy, barbarously and treach­erously assassinated seven hundred of their fellow-citizens; and carried their fury so far, that, one miserable fugitive having fled to the temple, they cut off his hands, by which he clung to the gates, and carrying him out of holy ground, immediately murdered him. By this impiety, says Herodotus, (not by the other many cruel assassinations) they offended the gods, and contracted an inexpiable guilt.

Nay, if we should suppose, what never happens, that a popular reli­gion were found, in which it was expressly declared, that nothing but morality could gain the divine favor; if an order of priests were insti­tuted to inculcate this opinion, in daily sermons, and with all the arts of persuasion; yet so inveterate are the people’s prejudices, that, for want of some other superstition, they would make the very attendance on these sermons the essentials of religion, rather than place them in virtue and good morals. The sublime prologue of Zaleucus’s⁴ laws inspired not the Locrians, so far as we can learn, with any sounder notions of the measures of acceptance with the deity, than were familiar to the Greeks.

This observation, then, holds universally: But still one may be at some loss to account for it. It is not sufficient to observe, that the people, every where, degrade their deities into a similitude with them­selves, and consider them merely as a species of human creatures, somewhat more potent and intelligent. This will not remove the diffi­culty. For there is no man so stupid, as that, judging by his natural reason, he would not esteem virtue and honesty the most valuable qualities, which any person could possess. Why not ascribe the same sentiment to his deity? Why not make all religion, or the chief part of it, to consist in these attainments?

Nor is it satisfactory to say, that the practice of morality is more dif­ficult than that of superstition; and is therefore rejected. For, not to mention the excessive penances of the Brachmans and Talapoins;⁵ it is certain, that the Rhamadan⁶ of the Turks, during which the poor wretches, for many days, often in the hottest months of the year, and in some of the hottest climates of the world, remain without eating or drinking from the rising to the setting sun; this Rhamadan, I say, must be more severe than the practice of any moral duty, even to the most vicious and depraved of mankind. The four lents of the Muscovites, and the austerities of some Roman Catholics, appear more disagreeable than meekness and benevolence. In short, all virtue, when men are recon­ciled to it by ever so little practice, is agreeable: All superstition is for ever odious and burthensome.

Perhaps, the following account may be received as a true solution of the difficulty. The duties, which a man performs as a friend or parent, seem merely owing to his benefactor or children; nor can he be wanting to these duties, without breaking through all the ties of nature and morality. A strong inclination may prompt him to the performance: A sentiment of order and moral obligation joins its force to these natural ties: And the whole man, if truly virtuous, is drawn to his duty, without any effort or endeavour. Even with regard to the virtues, which are more austere, and more founded on reflection, such as public spirit, filial duty, temperance, or integrity; the moral obligation, in our apprehen­sion, removes all pretension to religious merit; and the virtuous con­duct is deemed no more than what we owe to society and to ourselves. In all this, a superstitious man finds nothing, which he has properly performed for the sake of his deity, or which can peculiarly recommend him to the divine favor and protection. He considers not, that the most genuine method of serving the divinity is by promoting the happiness of his creatures. He still looks out for some more immediate service of the supreme Being, in order to allay those terrors, with which he is haunted. And any practice, recommended to him, which either serves to no purpose in life, or offers the strongest violence to his natural incli­nations; that practice he will the more readily embrace, on account of those very circumstances, which should make him absolutely reject it. It seems the more purely religious, because it proceeds from no mixture of any other motive or consideration. And if, for its sake, he sacrifices much of his ease and quiet, his claim of merit appears still to rise upon him, in proportion to the zeal and devotion which he discovers. In restoring a loan, or paying a debt, his divinity is nowise beholden to him; because these acts of justice are what he was bound to perform, and what many would have performed, were there no god in the uni­verse. But if he fast a day, or give himself a sound whipping this has a direct reference, in his opinion, to the service of God. No other motive could engage him to such austerities. By these distinguished marks of devotion, he has now acquired the divine favor; and may expect, in rec­ompense, protection and safety in this world, and eternal happiness in the next.

Hence the greatest crimes have been found, in many instances, compatible with a superstitious piety and devotion; Hence, it is justly regarded as unsafe to draw any certain inference in favor of a man’s morals, from the fervour or strictness of his religious exercises, even though he himself believe them sincere. Nay, it has been observed, that enormities of the blackest dye have been rather apt to produce super­stitious terrors, and increase the religious passion. Bomilcar, having formed a conspiracy for assassinating at once the whole senate of Carthage, and invading the liberties of his country, lost the opportunity, from a continual regard to omens and prophecies.⁷ Those who undertake the most criminal and most dangerous enterprizes are commonly the most superstitious; as an ancient historian remarks on this occasion. Their devotion and spiritual faith rise with their fears. Catiline was not con­tented with the established deities and received rites of the national reli­gion: His anxious terrors made him seek new inventions of this kind; which he never probably had dreamed of, had he remained a good cit­izen, and obedient to the laws of his country.⁸

       To which we may add, that, after the commission of crime, there arise remorses and secret horrors, which give no rest to the mind, but make it have recourse to religious rites and ceremonies, as expiations of its offences. Whatever weakens or disorders the internal frame promotes the interests of superstition: And nothing is more destructive to them than a manly, steady virtue, which either preserves us from disastrous, melancholy accidents, or teaches us to bear them. During such calm sun­shine of the mind, these spectres of false divinity never make their appearance. On the other hand, while we abandon ourselves to the nat­ural undisciplined suggestions of our timid and anxious hearts, every kind of barbarity is ascribed to the supreme Being, from the terrors with which we are agitated; and every kind of caprice, from the methods which we embrace in order to appease him. Barbarity caprice; these qual­ities, however nominally disguised, we may universally observe, form the ruling character of the deity in popular religions. Even priests, instead of correcting these depraved ideas of mankind, have often been found ready to foster and encourage them. The more tremendous the divinity is represented, the more tame and submissive do men become his ministers: And the more unaccountable the measures of acceptance required by him, the more necessary does it become to abandon our nat­ural reason, and yield to their ghostly guidance and direction. Thus it may be allowed, that the artifices of men aggravate our natural infirmi­ties and follies of this kind, but never originally beget them. Their root strikes deeper into the mind, and springs from the essential and uni­versal properties of human nature.