What God primarily does is to reveal himself , but he does so at least in part by telling us something about himself. The inscripturated form is itself revelation. Thus the Scriptures are God's revelation. Indeed, they are so regarded by the Jews of OT and NT times, not to mention by Christ himself. According to Neoorthodoxy, the Bible is the record of revelation, not revelation itself, which can only occur when there is an encounter between persons.
Later revelation builds on earlier revelation.
It is complementary and supplementary, not contradictory.