my memory is a faithful wife, and my imagination is a diligent little maiden
Kierkegaard here engages a metaphor to assert that he is not constructing a philosophy based on wearing rose-colored glasses. He want readers to know that he has come face to face with the more dreadful and terrifying aspects of existence and remembers them and those dreadful and terrifying aspects of life he has not confronted, he can certainly imagine.
Knight of Faith
The Knight of Faith is a metaphor for the person who loves without condition and thus attains a perfection of faith untainted by ethical relativism and is thus a form of moral absolutism. For Kierkegaard, the personification of this metaphor is Abraham and his trust in God.
the butterfly has entirely forgotten that it was a caterpillar
This assertion is intended as a metaphor of the lack of consciousness of lower animals and how this consciousness separates man from the beasts. Awareness of what he is an essential trait of humanity and the aspect of knowing and memory relates to issues of guilt and faith.
I am convinced that God is love
The belief expressed in this metaphor is the central tenet of Kierkegaard’s conception of faith. Faith in god in inextricably linked to faith in love and the ability to express love as one expresses faith is the locus of his argument.
Abraham is the representative of faith
The metaphorical impetus for this entire philosophical discussion is encapsulated. Not only is Abraham the representative of faith for Kierkegaard, but history offers no analogue. Abraham is unique is not just meeting the qualities of a Knight of Faith, but in being the only realization of those qualities.