Between 200-300AD, prior to the canonization of the Bible, and the reign of emperor Constantine the earliest and fiercest divisions in the Church did not pit “scriptural” Christians against “extra-biblical” innovators. They arose, rather, from disagreements over what the Scriptures meant. Tertullian complained that “heretics make use of the scriptures and…find support for their blasphemies from precedents [God] has provided.” Indeed, he moaned about “that sentence” they always “bring forward to justify” their restless speculation: “It is written.” Deemed a heretic by the First Council of Nicaea of 325, Arius and his opponents drew many of their proof-texts from the same Gospel: The Gospel According to John. Arius cited John 3:35, 14:28, and other passages to argue that Jesus is subordinate to the Father. Saint Athanasius invoked John 1:1-2,20:28, and others to establish the eternal deity of Jesus Christ.
The Church sought the truth in the apostolic tradition: the rule of faith, the scriptures, the words of liturgical worship and the authority of the bishops who held legitimate succession. These were the sure measures of biblical interpretation. Christians lived in an interpretive community that transcended their current historical moment, with its fads and intellectual fashions. They interpreted the Bible from within the communion of saints. Since Christ gave both Scripture and Tradition to the Apostles, these two streams of revelation were mutually illuminating, mutually confirming. The opponents of Arius, for example, could demonstrate that Christians in every age (for the previous 300yrs) had worshipped Christ as God.
Tertullian observed: “We do not take our scriptural doctrine from the parables, but we interpret the parables according to our doctrine. Nor do we labor hard to twist all things to avoid contradictions.” Our spiritual ancestors recognized the limits of their own understanding, and they trusted God to be consistent, even if his reasons eluded them from time to time.