Justin, as a student of Plato and Aristotle, fell into conversation with an old Cristian who made him see that although he knew about God he did not know God personally, and this revelation led to his being baptized Christian.
As a very studious and devout Christian, he opened as school for Christianity next to the Roman senate. When he heard senators making accusations, he posted corrections for what they said. For instance, when a Roman senator declared that Christians worshipped a goat , Justin, in 150 A.D. posted the posted the following description of our Mass.
"On that day which is called after the sun, all who are in the towns and in the country gather together for a communal celebration. And then the memoirs of the Apostles or the writings of the Prophets are read as much as time permits.
After the reader has finished his task, the one presiding gives an address, earnestly admonishing his hearers to practice these beautiful teachings in their lives.
Then, together all stand and recite prayers. and bread and wine mixed with water are brought, and the president offers prayers and thanksgivings as much as in him lies. The people chime in with Amen.
Then takes place the distribution to all attending of the things over which the thanksgiving has been spoken, and the deacons bring a portion to the absent. Besides, those who are well to do give whatever they will. What is gathered is deposited with the one presiding who therewith helps widows and orphans."