Dr. Jung often mentions the great influence Meister Eckhart who lived between the 11th and 12th century had upon his work.
Let's observe on example of this:
First read a portion of one of Meister Eckhart's sermons.
"St. John says: “See how great is the love that the Father has shown us, that we are called and are the children of God, “ (1 John 3:1).
He says not only “we are called” but “we are.”
So I say that just as a man cannot be wise without wisdom, so he cannot be a son without the filial nature of God’s Son, without having the same being as the Son of God has-just as being wise cannot be without wisdom.
And so, if you are the Son of God, you can only be so by having the same being of God that the Son has.
But this is “now hidden from us”; and after that it is written, “Beloved, we are the Sons of God.” And what do e know?-That is what he adds, “and we shall be like him.” (1 John 3:2), that is, the same as he is: the same being, experiencing and understanding-everything he is, when we see him as God.
So I say God could not make me the son of God if I had not the nature of God’’s Son, any more than God could make me wise if I had not wisdom.
How are we God’s sons?
We do not know yet: “it does not yet appear” to us, all we know is that he says we shall be like Him. There are certain things that hide this knowledge in our souls and conceal it from us. ~Meister Eckhart, Sermon Seven, (pf 7, Q 76, QT 35)
Next observe Illustration 64 from The Red Book and read the corresponding Commentary written by Dr. Jung.
Are we not sons of the Gods? Why should Gods not be our children? If my father the God should die, a God child should arise from my maternal heart.
Since I love the God and do not want to leave him. Only he who loves the God can make him fall, and the God submits to his vanquisher and nestles in his hand and dies in the heart of him who loves him and promises him birth.
My God, I love you as a mother loves the unborn whom she carries in her heart. Grow in the egg of the East, nourish yourself from my love, drink the juice of my life so that you will become a radiant God.
We need your light, oh child. Since we go in darkness, light up our paths. May your light shine before us, may your fire warm the coldness of our life. We do not need your power but life.
What does power avail us? We do not want to rule. We want to live, we want light and warmth, and hence we need yours. Just as the greening earth and every living body needs the sun, so we as spirits need your light and your warmth. A sunless spirit becomes the parasite of the body. But the God feeds the spirit. ~Carl Jung; Red Book
[I heartily recommend "The Complete Mystical Works of Meister Eckhart for those interested in finding even more profound correspondences in the psychological discoveries and experiences of Meister Eckhart and Dr. Jung.]