When first reading the Fathers of the Church one may be tempted to smile at the quaintness of those phenomenological writers of old and to congratulate more recent theologians for advancing from simplistic and obvious tenets of faith, like the Divinity of Jesus, to more complex and intellectually challenging fields like the mechanisms of justification and the temporal exchanges of merit concerning purgatory. Vatican I quoted St. Vincent of Lerins' Commonitory which gives a brief exposé on the development of doctrine, a concept which also influenced John Henry Newman in his conversion.
However, intellectual fulfillment and spiritual piety will profit very little from advanced schools of theology in the modern day. Knowing the concept of a sacramental form and how to deduce it for Confirmation will not profit the soul of modern man, whose religious experience rarely extends beyond an occasional Christmas Mass and whose education is confined to the dullest and most monotonous of topics (specialized training, business courses, IT etc). What could appeal to these people?
The Church Fathers are the most obvious choice. The Fathers, particularly the Apostolic Fathers, did not rely as heavily on technical terms, particular philosophical traditions, and an established Christian culture as did the Scholastics, the casuists, the neo-Scholastics, and the manualists. Their own culture was marked by either persecution or confusion. A few of them came from neo-Platonist backgrounds (St. Augustine, Origen, and St. Dionysius), but even those writers' influence is inessential to accepting their claims. Another advantage of the Fathers is that they did not live in an orthodox Christian society. They were either persecuted by the Empire, fighting heresy, and persecuted by heretics. Their appeals were to laity in homilies and letters, and to other thinkers in tracts, although even their educated audiences were not "theologians" in the later sense of the word. Consequentially their language, framework, and approach is much more intuitive for modern readers, appealing to instinct rather than specialized traditions of logic. Also, their claims are easier to check. Every American home owns some sort of Bible and dozens of Bibles are available for free online in English alone. Finding a chapter of Mark is much easier for the lax modern man than finding and understanding the Common Doctor.
Perhaps the greatest strength of the Fathers is that the bulk of their tracts and polemics focus on the consubstantiality of the Trinity and the Divinity of Jesus Christ. The Church may have settled this matter in the year 325AD, but Arianism is far from gone. One might say that the error of Arius is as prevalent now as it was in the time of Diocletian, and Christianity is more hated now than it has been in any time since Diocletian. Why should Catholics focus their sights on the Fathers and the Trinity? Because sacramental forms, transubstantiation, indulgences, propitiation, and Papal infallibility are all quite useless without a proper understanding of Who God is and Who Jesus Christ is. Case in point a dear friend of mine.
My friend, let us pretend his name is George, grew up in a gay household, was nominally Catholic, never received any form of religious instruction whatsoever, served 15 years in the military, was stationed at Ground Zero for the two weeks following 9/11, received a very prized but specialized education, and now works in the political sphere to promote American imperialism. What he has kept from the Church is an understanding of guilt. George is a good man and a good friend, but his understanding of Christ and Christianity is quite troubled. Like most modern Americans he accepts the existence of God and calls Jesus the "Son of God," but cannot identify Him with God. "Jesus" is George's "buddy" while "God" is George's maker. I once shared with George that haunting Byzantine petition "That the end of our life may be painless, unashamed, Christian, and peaceful, and for a good answer before the awesome judgment seat of Christ, let us ask! Grant this, O Lord!" "God" will judge George, but "Jesus" will intervene and assure George of his salvation.
Unlike the Arians, whose theological malice existed among a world familiar with Scripture and the Sacraments, George has no religious education and has been trained by the world to have no familiarity with the humanities or with the religious imagination. George has been molded in ignorance, but ignorance will not split the Trinity into three separate creatures. When I shared with George that eternal sentence of Our Lord's "Before Abraham was I am" (John 8:58) and intimated that, with no material objects Jesus could not have been fashioned but rather was "begotten," the poor man was horrified. He has thought, and might still, that "Jesus" was a super-special "Son" made by "God" for our benefit. The concept of Three Divine Persons in One God nearly caused his mechanistic, rational mind to explode—quite an accomplishment considering George's high IQ. He pondered the matter for a short time and then, as the world trains modern men to do, he swept the matter under the rug and forgot about it.
I have attempted the rationalized explanation of the Trinity before with George and gotten no where with it. A mind trained in logic normally can only function according to the assumptions accepted in its era. Although right wing politically, the assumptions of Goerge's era descend from the materialism of Marx, Engels, and the Capitalists, and from the science of Darwin, and from the pseudo-scientific "social sciences" of economists such as Keynes and the neo-classicists. The best path in my experience is to appeal to more basic and human elements when discussing the Divine, elements shared by most people. My conversations with the un-churched and un-believing are the primary sources of my frustration with legalistic theology which I voice here so often. St. Gregory Nazianzen's concept of the Trinity based on the process of thinking—wherein the Father is the mind, the Son is speech and words, and the Holy Spirit the breath flowing from the mouth—has been far more successful with George than most methods of teaching the Trinity since then. Similarly, explaining the Incarnation to George became easier with that aphorism from St. Athanasius, "God became man so that man might become God." After assuring himself that God had not smited us for such a "disturbing" thought, he began to understand the Church's teaching on the two natures of Christ and on the Trinity. Is this obsession over the Trinity too harsh given George's upbringing? Perhaps, but we Catholics must not forget that the un-revised Creed of Nicaea ended with "But those who say: 'There was a time when he was not;' and 'He was not before he was made;' and 'He was made out of nothing,' or 'He is of another substance' or 'essence,' or 'The Son of God is created,' or 'changeable,' or 'alterable'—they are condemned by the Holy Catholic and Apostolic Church."
As the world becomes increasingly secular few people will have the concerns of past times. In 1960 America, when Ike was cleaning out his desk draws to make room for Kennedy, most people asked whether the Catholics or the protestants were right about what Christianity is. These days the few curious people are asking if God even exists. Those who accept the existence of God construct a fitting God in their minds and a fitting Jesus, too. Lost in all this is the Trinity and the Jesus of the New Testament. Lost is God as He is. Before we can discuss the Immaculate Conception we must be able to communicate the most basic and absolutely fundamental parts of the faith, above all, Who God is. The Fathers can help.