The description of himself as the Son of God, Messianic though it may have been in its original conception, lies very much nearer to our modern way of thinking than the other, for Jesus himself gave a meaning to this conception which almost takes it out of the class of messianic ideas, or at all events does not make its inclusion in that class necessary to a proper understanding of it. On the other hand, if we do not desire to be put off with a lifeless word, the description of himself as the Messiah is at first blush one that is quite foreign to our ideas. Without some explanation we cannot understand, nay, unless we are Jews, we cannot understand at all, what this post of honour means and what rank and character it possesses. It is only when we have ascertained its meaning by historical research that we can ask whether the word has a significance which in any way survives the destruction of the husk in which it took shape in Jewish political life.
Let us first of all consider the designation, “Son of God.” Jesus in one of his discourses made it specially clear why and in what sense he gave himself this name. The saying is to be found in Matthew, and not, as might perhaps have been expected, in John: “No man knoweth the Son but the Father; neither knoweth any man the Father, save the Son, and he to whomsoever the Son will reveal him.” It is “knowledge of God” that makes the sphere of the Divine Sonship. It is in this knowledge that he came to know the sacred Being who rules heaven and earth as Father, as his Father. The consciousness which he possessed of being the Son of God is, therefore, nothing but the practical consequence of knowing God as the Father and as his Father. Rightly understood, the name of Son means nothing but the knowledge of God. Here, however, two observations are to be made: Jesus is convinced that he knows God in a way in which no one ever knew Him before, and he knows that it is his vocation to communicate this knowledge of God to others by word and by deed—and with it the knowledge that men are God’s children. In this consciousness he knows himself to be the Son called and instituted of God, to be the Son of God, and hence he can say: My God and my Father, and into this invocation he puts something which belongs to no one but himself. How he came to this consciousness of the unique character of his relation to God as a Son; how he came to the consciousness of his power, and to the consciousness of the obligation and the mission which this power carries with it, is his secret, and no psychology will ever fathom it. The confidence with which John makes him address the Father: