Athenagoras (d. c. 200 AD?) was an able Christian apologist in the early church. Before he became a Christian, he was a Greek philosopher. After he became a Christian, he used his gifts to defend the Christian faith against the opposition of the Roman government that was hostile to Christians. One of Athenagoras’ writings that survived is called “A Plea for the Christians,” which was written to Roman rulers and philosophers. The entire work is certainly worth reading; below is one part that stood out to me.
“Since, therefore, the unity of the Deity is confessed by almost all (even non-Christian Greek philosophers of the past), even against their will, when they come to treat of the first principles of the universe, and we in our turn likewise assert that He who arranged this universe is God – why is it that they can say and write with impunity (exemption from punishment) what they please concerning the Deity, but that against us a law lies in force, though we are able to demonstrate what we apprehend and justly believe, namely, that there is one God, with proofs and reason accordant with truth?”
“For poets and philosophers, as to other subjects so also to this, have applied themselves in the way of conjecture (speculation), moved, by reason of their affinity with the afflatus (impulse) from God, each one by his own soul, to try whether he could find out and apprehend the truth; but they have not been found competent to fully apprehend it, because they thought fit to learn, not from God concerning God, but each one from himself; hence they came to their own conclusion respecting God, and matter, and forms, and the world.”
“But we have for witnesses of the things we apprehend and believe, prophets, men who have pronounced concerning God and the things of God, guided by the Spirit of God. And you too will admit, excelling all others as you do in intelligence and in piety towards the true God, that it would be irrational for us to cease to believe in the Spirit from God, who moved the mouths of the prophets like musical instruments, and to give heed [instead] to mere human opinions.”
Athenagoras is saying that not only was it unfair that Christians are punished for their beliefs about God while philosophers are not, it is also true that philosophers did not learn about God from God, so they are wrong in their beliefs. Christians, however, learn about the true God from his prophets, whom the Spirit used to speak God’s truth. To put it simply, Christians learn about God from God – that is not irrational nor should it be the reason for punishment and persecution!
The entire work can be found in volume 2 of The Ante Nicene Fathers – page 129ff.