Of all the systems of ...

Of all the systems of religion that ever were invented, there is no more derogatory to the Almighty, more unedifying to man, more repugnant to reason, and more contradictory to itself than this thing called Christianity. Too absurd for belief, too impossible to convince, and too inconsistent for practice, it renders the heart torpid or produces only atheists or fanatics. As an engine of power, it serves the purpose of despotism, and as a means of wealth, the avarice of priests, but so far as respects the good of man in general it leads to nothing here or hereafter.
Of all the systems of religion that ever were invented, there is no more derogatory to the Almighty, more unedifying to man, more repugnant to reason, and more contradictory to itself than this thing called Christianity. Too absurd for belief, too impossible to convince, and too inconsistent for practice, it renders the heart torpid or produces only atheists or fanatics. As an engine of power, it serves the purpose of despotism, and as a means of wealth, the avarice of priests, but so far as respects the good of man in general it leads to nothing here or hereafter.

Quotes from the same author

A long habit of not thinking a thing wrong gives it a superficial appearance of being right.
The World is my country, all mankind are my brethren, and to do good is my religion.
The most formidable weapon against errors of every kind is reason.
Arms, like laws, discourage and keep the invader and plunderer in awe and preserve order.
The balance of power is the scale of peace. The same balance would be preserved were all the world not destitute of arms, for all would be alike; but since some will not, others dare not lay them aside ... Horrid mischief would ensue were one half the world deprived of the use of them ... the weak will become prey to the strong.