What is Shakespeare trying to communicate about life in this passage spoken by the character Macbeth?

Shakespear is trying to communicate through Macbeth that life is hopeless and despairing. In this passage Macbeth has just previously heard about his wife’s death and is currently in deep depression. In his soliloquy he is speaking about life and its purposes and fortune. Shakespear has used Macbeth to communicate what life is and its meaning in the play. Macbeth states “life is but a walking shadow”, he is using a metaphor to describe life and how it is meaningless. That nothing we really see in life is substantial, until perhaps it is too late.