Not being "unreasonable" is, of course, one of the skills for which Satan is noted just as his ability to quote fluently from Scripture. Yet both Arius and Nestorius are clearly heresiarchs whilst St. Athanasius and St. Cyril are great fathers of the universal Church.
This issue was addressed by St. Vincent of Lerins in The Commonitory, "Some one may ask, Do heretics also appeal to Scripture? They do indeed, and with a vengeance; for you may see them scamper through every single book of Holy Scripture." His rule, therefore for the authentic interpretation of scripture as commended by holy and learned men, was to "interpret the sacred Canon according to the traditions of the Universal Church and in keeping with the rules of Catholic doctrine, in which Catholic and Universal Church, moreover, they must follow universality, antiquity, consent."
Similarly, Tertullian (De praescriptione haereticorum), in his battle against the 3rd century heretics, asserted that the only true understanding of the Scriptures belonged to the Church, so for those outside the household of faith, they were simply an array of disconnected passages, a dead letter, which they might try to use for their own ends, "For wherever it shall be manifest that the true Christian rule and faith shall be, there will likewise be the true Scriptures and expositions thereof, and all the Christian traditions."
Abiding in communion with those ancient apostolic sees which have jealously guarded the integrity of the faith is a sound means of maintaining that; whilst those who wander off must not be surprised that the further you get from the household of faith the louder the clamour of discordant voices and the greater the chance of being "tossed to and fro, and carried about with every wind of doctrine, by the sleight of men, and cunning craftiness, whereby they lie in wait to deceive." (Ephesians IV: 14) It is hardly surprising, therefore, that the fathers used the imagery of a ship bringing us safe to harbour over tempestuous seas when describing the Church of God!