St. John Henry Newman said, “To be deep in history is to cease to be Protestant.” He was speaking in part from personal experience, since his study of the history of the early Church convinced him that it was Catholic.
It’s common to hear converts from Protestantism cite the Church Fathers as a catalyst for their switch to Catholicism.
While you generally shouldn’t start a conversation with a Protestant by citing Newman’s quote, be prepared to bring Church history into the discussion eventually.
Consider these tips.
Read up on the Church Fathers first.
Study their actual writings, as well as commentaries on them to know what the early Church taught. You can find almost all the extant works of the Fathers for free online (New Advent is one source
Many Catholic teachings and practices are found in the works of the Fathers. Take for example this first-century testimony to apostolic succession from Pope Clement I’s Letter to the Corinthians:
“Our apostles also knew, through our Lord Jesus Christ, that there would be strife on account of the office of the episcopate. For this reason, therefore, inasmuch as they had obtained a perfect fore-knowledge of this, they appointed those [ministers] already mentioned, and afterward gave instructions, that when these should fall asleep, other approved men should succeed them in their ministry. We are of the opinion, therefore, that those appointed by them, or afterward by other eminent men, with the consent of the whole church, and who have blamelessly served the flock of Christ, in a humble, peaceable, and disinterested spirit, and have for a long time possessed the good opinion of all, cannot be justly dismissed from the ministry.”
Read every passage in context, so you don’t misrepresent the meaning to further a belief or argument (aka proof-texting). Also, study history to learn the environment in which each Church Father taught. This is especially important when the Fathers are refuting heresy. You won’t properly understand what they’re teaching unless you know the heresy they were fighting, be it Arianism, Donatism, or Marcionism.
Focus on the Fathers up to 300 A.D.
The reason for this is that many Protestants still disseminate the oft-refuted idea that the Catholic Church was started by Emperor Constantine in the 300s A.D. Because of that, any Church Fathers you refer to from that time on may be dismissed. It’s better to rely on earlier Fathers, such as St. Clement of Rome, St. Ignatius of Antioch, St. Justin Martyr, and St. Irenaeus.
The other great thing about these earliest Fathers is that many of their works are shorter and more digestible than those of later Fathers, like St. Augustine.
Don’t expect to find every teaching explicitly taught in the early Church.
The sacred Deposit of Faith has been faithfully passed on from the apostles to their successors. But doctrine develops — not in the sense that God’s revelation changes or evolves (that would be heresy) — but that our understanding of it grows with time.
Therefore, you shouldn’t expect to find the dogma of Mary’s Assumption clearly and systematically laid out in the earliest Church Fathers. You’ll have to turn to other evidence, such as the stunning fact that no Church Father said anything about Mary’s remains despite the early Church keeping meticulously account of the relics of its saints.
While all these tips are meant to help you have a fruitful discussion with Protestants, they’ll benefit you as well. We as Catholics need to be historically literate, especially since Catholic Tradition and traditional values are under attack in many parts of the world.
Plus, the writings of the early Church are spiritually rich and make for great reading if you want to deepen your faith.