The word religion is a word of forced application when used with respect to the worship of God. The root of the word is the Latin verb ligo, comes religo, to tie or bind over again, to make more fast - from religo, comes the substantive religo, which, with the addition of n makes the English substantive religion.
The French use the word properly: when a woman enters a convent she is called a novitiate, that is, she is tied or bound by that oath to the performance of it. We use the word in the same kind of sense when we say we will religiously perform the promise that we make.
But the word, without referring to its etymology, has, in the manner it is used, no definite meaning, because it does not designate what religion a man is of. There is the religion of the Chinese, of the Tartars, of the Brahmins, of the Persians, of the Jews, of the Turks, etc.
The word Christianity is equally as vague as the word religion. No two sectaries can agree what is it. It is lo here and lo there. The two principal sectaries, Papists and Protestants, have often cut each other's throats about it.
The Papists call the Protestants heretics, and the Protestants call the Papists idolaters. The minor sectaries have shown the same spirit of rancor, but as the civil law restrains them from blood, they content themselves with preaching damnation against each other.
The word protestant has a positive signification in the sense it is used. It means protesting against the authority of the Pope, and this is the only article in which the Protestants agree. In every other sense, with respect to religion, the word protestant is as vague as the word Christian.
When we say an Episcopalian, a Presbyterian, a Baptist, a Quaker, we know what those persons are, and what tenets they hold; but when we say a "Christian," we know he is not a Jew nor a Mahometan, but we know not if he be a trinitarian or an anti-trinitarian, a believer in what is called the immaculate conception, or a disbeliever, a man of seven sacraments, or of two sacraments, or of none. The word "Christian" describes what a man is not, but not what he is.
The word theology, from Theos, the Greek word for God, and meaning the study and knowledge of God, is a word that strictly speaking belongs to Theists or Deists, and not to the Christians. The head of the Christian Church is the person called Christ, but the head of the Church of the Theists, or Deists, as they are more commonly called (from Deus, the Latin word for God), is God Himself; and therefore the word "Theology" belongs to that Church which has Theos or God for its head, and not to the Christian Church which has the person called Christ for its head. Their technical word is Christianity, and they cannot agree what Christianity is.
The words revealed religion, and natural religion, also require explanation. They are both invented terms, contrived by the Church for the support of priestcraft. With respect to the first, there is no evidence of any such thing, except in the universal revelation that God has made of His power, His wisdom, His goodness, in the structure of the universe, and in all the works of creation.
We have no cause or ground from anything we behold in those works to suppose God would deal partially by mankind, and reveal knowledge to one nation and withhold it form another, and then damn them for not knowing it. The sun shines an equal quantity of light all over the world - and mankind in all ages and countries are endued with reason, and blessed with sight, to read the visible works of God in the creation, and so intelligent is this book that he that runs may read.
We admire the wisdom of the ancients, yet they had no Bibles nor books called "revelation." They cultivated the reason that God gave them, studied Him in His works, and arose to eminence.
As to the Bible, whether true or fabulous, it is a history, and history is not a revelation. If Solomon had seven hundred wives, and three hundred concubines, and if Samson slept in Delilah's lap, and she cut his hair off, the relation of those things is mere history that needed no revelation from heaven to tell it; neither does it need any revelation to tell us that Samson was a fool for his pains, and Solomon too.
As to the expressions so often used in the Bible, that the word of the Lord came to such an one, or such an one, it was the fashion of speaking in those times, like the expression used by a Quaker, that the spirit moveth him, or that used by priests, that they have a call. We ought not to be deceived by phrases because they are ancient. But if we admit the supposition that God would condescend to reveal Himself in words, we ought not to believe it would be in such idle and profligate stories as are in the Bible; and it is for this reason, among others which our reverence to God inspires, that the Deists deny that the book called the Bible is the Word of God, or that it is revealed religion.
With respect to the term natural religion, it is upon the face of it, the opposite of artificial religion, and it is impossible for any man to be certain that what is called revealed religion is not artificial.
Man has the power of making books, inventing stories of God, and calling them revelation, or the Word of God. The Koran exists as an instance that this can be done, and we must be credulous indeed to suppose that this is the only instance, and Mahomet the only impostor. The Jews could match him, and the Church of Rome could overmatch the Jews. The Mahometans believe the Koran, the Christians believe the Bible, and it is education makes all the difference.
Books, whether Bibles or Korans, carry no evidence of being the work of any other power than man. It is only that which man cannot do that carries the evidence of being the work of a superior power. Man could not invent and make a universe - he could not invent nature, for nature is of divine origin. It is the laws by which the universe is governed.
When, therefore, we look through nature up to nature's God, we are in the right road of happiness, but when we trust to books as the Word of God, and confide in them as revealed religion, we are afloat on the ocean of uncertainty, and shatter into contending factions. The term, therefore, natural religion, explains itself to be divine religion, and the term revealed religion involves in it the suspicion of being artificial.
To show the necessity of understanding the meaning of words, I will mention an instance of a minister, I believe of the Episcopalian Church of Newark, New Jersey. He wrote and published a book, and entitled it "An Antidote to Deism." An antidote to Deism must be Atheism. It has no other antidote - for what can be an antidote to the belief of a God, but the disbelief of God? Under the tuition of such pastors, what but ignorance and false information can be expected?