Reading and searching the Scriptures without the writings of the church fathers and the saints, as through a looking glass, clear, colored and crystalline, and in pristine vision, we naturally begin to question the veracity of our interpretation - leading to pseudo confidence as fundamentalists or other denominations. We operate in one reference point explicitly but many others without knowing, those of modern culture and concepts.
When we read the Bible with the writings of the church fathers and saints, we read and think from two, three, even four points of reference, different ages and eras and ways of thinking, all in agreement. When we do so, we may see the truth more clearly and free ourselves from the situation of having a reference point in the Bible and all the modern interpretations from the world and its regard for biblical dynamics, constructs, and concepts that seep in as alternative references without our knowledge or awareness.
For example, with modern thought constructs, sin may be defined as a mistake. All have made mistakes one may say. So we must seek perfection. However, to the church fathers, sin is not only a mistake, it is separation from God. Therefore, what we truly need is connection to God, union with Christ, to be in him and he in us. This is what leads to heaven and eternal life.