[I have] the conviction that learning to grasp the unity of the Bible, of its one overall message from Genesis to Revelation, is necessary for a right understanding of the meaning of any individual text.That quote is from Grame Goldsworthy in his Preface to According To Plan: The Unfolding Revelation of God in the Bible.
How important is it that we grasp the ONE message of the Bible? Let's imagine a scenario:
A mean person is about to throw a rock at your head that is going to end your life. In that moment, just before the stone connects with your cranium, would you be able to give a brief overview of the history of God's revelation of Himself in Scripture and His saving purposes in Christ? Stephen could.
It is my deep conviction that every part of the Bible is given its fullest meaning by the saving work of Christ, who restores a sinful, fallen creation and makes all things new (Preface, According to Plan).