Heresy is not so much rejecting as selecting. The heretic simply selects the parts of the Scripture he wants to emphasize and lets the rest go.
This is shown by the etymology of the word heresy and by the practice of the heretic. “Beware,” an editorial scribe of the fourteenth century warned his readers in the preface to a book. “Beware thou take not one thing after thy affection and liking, and leave another: for that is the condition of an heretique. But take everything with other.” The old scribe knew well how prone we are to take to ourselves those parts of the truth that please us and ignore the other parts. And that is heresy.
Almost every cult with which we have any acquaintance practices this art of selecting and ignoring. The no-hell cults, for example, habitually stress everything in the Bible that seems to support their position and play down or explain away all the passages that deal with eternal punishment.