The philosophy of Rome owed much to Greece, and so it is not surprising to find some of the same critical themes later taken up by Roman writers and philosophers. In fact, it's hard to find much that's entirely new and original in Roman philosophy — the Romans tended to eschew speculative philosophy in favor of more practical concerns like morality and how to live a good life. Even here, though, they tended to lean heavily on Greek writings.
Lucretius (98?-55? BCE) was Roman poet who expounded the philosophical materialism of Greek philosophers Democritus and Epicurus and is in fact the main source for contemporary knowledge of Epicurus' thought. Like Epicurus, Lucretius sought to free humanity from the fear of death and of the gods, which he considered the main cause of human unhappiness.
He insisted that the soul is not a distinct, immaterial entity but instead just a chance combination of atoms that does not survive the body. He also postulated purely natural causes for earthly phenomena in order to prove that the world is not directed by divine agency and that fear of the supernatural is consequently without reasonable foundation. Lucretius did not deny the existence of gods, but like Epicurus he conceived of them as having no concern with the affairs or destiny of mortals.
"Too often in time past, religion has brought forth criminal and shameful actions. ...How many evils has religion caused!"
"The nature of the universe has by no means been made through divine power, seeing how great are the faults that mar it."
"All religions are equally sublime to the ignorant, useful to the politician, and ridiculous to the philosopher."
"Fear was the first thing on earth to make gods."
"Not they who reject gods are profane, but those who accept them."
"We, peopling the void air, make gods to whom we impute the ills we ought to bear."
"There is no murky pit of hell awaiting anyone. ...Mind cannot arise alone without body, or apart from sinews and blood. ...You must admit, therefore, that when the body has perished, there is an end also of the spirit diffused through it. It is surely crazy to couple a mortal object with an eternal and suppose that they can work in harmony and mutually interact."
Other Roman Writers
Few Roman writers had such a thoroughly developed critique of gods and religion, but many other certainly had their skepticism:
"It is expedient that gods should exist; since it is expedient, let us believe that they do." (Ovid)
"From the moment of death onward, the body and soul feel as little as they did before birth." (Pliny the Elder)
"The superstitious man wishes he did not believe in gods, as the atheist does not, but fears to disbelieve in them." (Plutarch)
"Religion is regarded by the common people as true, by the wise as false, and by the rulers as useful." (Seneca)
"It is for the good of states that men should be deluded by religion." (Statius)
There is certainly still quite a lot material which is not covered here, but nevertheless this should suffice to show that skepticism and critique of religion and theism are not recent inventions. Nor are they even inventions of educated Westerners. Moreover, much of what we say today in critique of religion has already been prefigured in much earlier writing. If knowledge of the influence of religion is important to a well-rounded education, then so is knowledge of critiques of religion. This, hopefully, will serve as a beginning for some people.