“So, too, it is not yet knowledge of the gospel when you know these doctrines and commandments, but only when the voice comes that says, ‘Christ is your own, with his life, teaching, works, death, resurrection, and all that he is, has, does, and can do.’”  

Luther, Preface to the New Testament – emphasis Shepherd’s.

(Timothy F. Lull, Martin Luther’s Basic Theological Writings, p. 116)

Knowledge of the gospel (for Luther, ‘gospel’ = the promise of God fulfilled in our midst) is the same as knowledge of Christ, where ‘knowledge’, understood in terms of Hebrew logic, always means ‘intimate personal participation in Christ himself giving rise to the transformation of the believer.’

Knowledge of the gospel can’t be reduced to an apprehension of doctrines and commandments; neither can it be reduced to (although it must always include) Christ’s

Life: his rendering God the obedience humans are supposed to;

Teaching: his delineation of and pioneering of the ‘Way’ of discipleship;

Works: his instantiating God’s incursion into the world and into our lives;

Death: his propitiation and expiation;

Resurrection: his victory on our behalf, and his rulership arising from his victory.

We can ‘know’ all this in the sense of understand it and endorse it and assent to it, yet we know the gospel  (are intimately acquainted with Jesus Christ himself) only as we hear (and heed) the voice of the Person who is present to us.

In the history of Christian thought God’s impassivity has always been connected with God’s immutability.

According to Jaroslav Pelikan, in Hebrew understanding “the immutability of God was seen as the trustworthiness of his covenanted relation to his people in the concrete history of his judgement and mercy rather than as a primarily ontological category.”  (The Christian Tradition: A History of the Development of Doctrine, vol. I, p.22.)