The Age of Reason by Thomas Paine - Part 2, Footnotes

[The Marcionists (a Christian sect) asserted that the evangelists were filled with falsities. The Manichaeans, who formed a very numerous sect at the commencement of Christianity, rejected as false all the New Testament, and showed other writings quite different that they gave for authentic. The Corinthians, like the Marcionists, admitted not the Acts of the Apostles. The Encratites and the Sevenians adopted neither the Acts, nor the Epistles of Paul. Chrysostom, in a homily which he made upon the Acts of the Apostles, says that in his time, about the year 400, many people knew nothing either of the author or of the book. St. Irene, who lived before that time, reports that the Valentinians, like several other sects of the Christians, accused the scriptures of being filled with imperfections, errors, and contradictions. The Ebionites, or Nazarenes, who were the first Christians, rejected all the Epistles of Paul, and regarded him as an impostor. They report, among other things, that he was originally a Pagan; that he came to Jerusalem, where he lived some time; and that having a mind to marry the daughter of the high priest, he had himself been circumcised; but that not being able to obtain her, he quarrelled with the Jews and wrote against circumcision, and against the observation of the Sabbath, and against all the legal ordinances.—Author.] [Much abridged from the Exam. Crit. de la Vie de St. Paul, by N.A. Boulanger, 1770.—Editor.]" [On ancient Christian sects and how they differed about the New Testament text and found it full of errors and additions]

The Age of Reason by Thomas Paine - Part 2, Chapter 3

"The study of theology as it stands in Christian churches, is the study of nothing; it is founded on nothing; it rests on no principles; it proceeds by no authorities; it has no data; it can demonstrate nothing; and admits of no conclusion. Not any thing can be studied as a science without our being in possession of the principles upon which it is founded; and as this is not the case with Christian theology, it is therefore the study of nothing." [A harsh rebuke of Christianity]

"[if a] revolution in the system of religion takes place, every preacher ought to be a philosopher. Most certainly, and every house of devotion a school of science." [Replacing religion with philosophy and science]

The Age of Reason by Thomas Paine - Part 1, Chapter 13

Thomas Paine explaining the root of his displeasure with the core doctrine of Christianity and how repulsed he was at the story of God torturing and murdering his son as an excuse to save a minuscule portion of humanity who have little or no understanding of the message of Christ or what is written in the bible.

"From the time I was capable of conceiving an idea, and acting upon it by reflection, I either doubted the truth of the christian system, or thought it to be a strange affair; I scarcely knew which it was: but I well remember, when about seven or eight years of age, hearing a sermon read by a relation of mine, who was a great devotee of the church, upon the subject of what is called Redemption by the death of the Son of God. After the sermon was ended, I went into the garden, and as I was going down the garden steps (for I perfectly recollect the spot) I revolted at the recollection of what I had heard, and thought to myself that it was making God Almighty act like a passionate man, that killed his son, when he could not revenge himself any other way; and as I was sure a man would be hanged that did such a thing, I could not see for what purpose they preached such sermons. This was not one of those kind of thoughts that had any thing in it of childish levity; it was to me a serious reflection, arising from the idea I had that God was too good to do such an action, and also too almighty to be under any necessity of doing it. I believe in the same manner to this moment; and I moreover believe, that any system of religion that has anything in it that shocks the mind of a child, cannot be a true system.
"It seems as if parents of the christian profession were ashamed to tell their children any thing about the principles of their religion. They sometimes instruct them in morals, and talk to them of the goodness of what they call Providence; for the Christian mythology has five deities: there is God the Father, God the Son, God the Holy Ghost, the God Providence, and the Goddess Nature. But the christian story of God the Father putting his son to death, or employing people to do it, (for that is the plain language of the story,) cannot be told by a parent to a child; and to tell him that it was done to make mankind happier and better, is making the story still worse; as if mankind could be improved by the example of murder; and to tell him that all this is a mystery, is only making an excuse for the incredibility of it."

And a little aside on the magnitude of the universe and how little and limited the universe looks if we are to believe the scriptures:

"Though it is not a direct article of the christian system that this world that we inhabit is the whole of the habitable creation, yet it is so worked up therewith, from what is called the Mosaic account of the creation, the story of Eve and the apple, and the counterpart of that story, the death of the Son of God, that to believe otherwise, that is, to believe that God created a plurality of worlds, at least as numerous as what we call stars, renders the christian system of faith at once little and ridiculous; and scatters it in the mind like feathers in the air. The two beliefs can not be held together in the same mind; and he who thinks that he believes both, has thought but little of either."