16 What will you answer your father also? Who with greater grief will address you, saying, “You judged very ill of me, my son, when you supposed that I could have connived at the heathen. No one ever told me that there was an altar in the Roman Senate House, I never believed such wickedness as that the heathen sacrificed in the common assembly of Christians and heathen, that is to say that the Gentiles should insult the Christians who were present, and that Christians should be compelled against their will to be present at the sacrifices. Many and various crimes were committed while I was Emperor. I punished such as were detected; if any one then escaped notice, ought one to say that I approved of that of which no one informed me? You have judged very ill of me, if a foreign superstition and not my own faith preserved the empire.”
Source: Letters (New Advent)