"But you must continue in the things which you have learned and been assured of, knowing from whom you have learned them, and that from childhood you have known the Holy Scriptures, which are able to make you wise for salvation through faith which is in Christ Jesus. All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, that the man of God may be complete, thoroughly equipped for every good work." - 2 Timothy 3:14-17 (NKJV).
As a Christian, I believe that when Paul wrote those words, under inspiration of God, he meant them. He did not mean "the scriptures aren't nearly clear enough for you to understand". He did not mean "the scriptures aren't really enough for a complete walk with God". He certainly did not mean "God got it wrong, wait a century or two for uninspired men to show up and clarify what He really meant". No, I believe that Paul meant what Paul wrote.
"Not so", say certain heretics. "Don't go to the Bible for doctrine, come to us. We'll tell you what God really meant." Their justification? The so-called Church "Fathers". Men living between the second and 8th centuries, giving their understanding of scripture, are treated as being somehow more authoritative than those very.
Remember, according to Paul, an Apostle of Christ, all scripture is inspired by God (the original Greek literally says "God breathed"), and is useful (as opposed to unintelligible) for doctrine, reproof, correction, and instruction in righteousness, that the man of God may be complete and thoroughly equipped for every good work. That really doesn't leave a lot of room for interpretation. So really, while the Church "Fathers" may sometimes be useful, they are not authoritative. If a Church "Father" is right, they are right, but they are merely agreeing with what has already been revealed. That doesn't give them a shred of authority. By contrast, when a Church "Father" is wrong, which can happen, they are wrong, and the Bible supersedes them.
It is significant that the Church Fathers themselves lived by this philosophy. They studied scripture, they quoted scripture, they encouraged others to do the same. Much like the prophets and Apostles did, and even Christ Himself (e.g. Acts 17:11, John 5:46). If the Church "Fathers" saw how much they were almost deified in today's world, they would be very upset.
One way heretics try to rescue their methodology is to point out that some of the Church Fathers (in today's example, Ignatius) actually heard the Apostles. Thus, we should listen to them. It doesn't take much to see the flaw in this reasoning. Is Ignatius alive today? Is there a single church in which he has preached recently? Ignatius of Antioch died in 108 A.D., not too long after the closing of the canon. So, heretics have invented a problem, but they have failed to solve it. The mythical problem is that the Apostles died, and so we need someone to help us interpret them. The solution is to appeal to an interpreter who has also been dead for almost 2,000 years. In other words, the heretic is effectively claiming "you can't interpret the scriptures yourself. You must accept my interpretation of my church's interpretation of Ignatius' interpretation of the scriptures". That's quite the rusty chain...
As with all things, the primary source is the greatest source. The Bible is more than just a primary source. It is, in fact, an infallible source. It is the word of God Himself, delivered by His hand-chosen servants. Though there was error in the men themselves (after all, they were sinners), they wrote as the Holy Spirit guided them (2 Peter 1:19-21), meaning the words you read in the scriptures, so far as they are correctly translated, are completely inerrant. By contrast, the Church Fathers had the same capacity for error, without the safeguards of divine inspiration. The Church Fathers, from Ignatius of Antioch to John of Damascus, were sinful men with varying levels of faith and understanding. Far better to rely on that which God has revealed than that which people say about what God has revealed.