Second phrase:

(He is) One implies that the human spirit, which is connected to most species in the universe and thereby overwhelmed with misery and confusion, finds therein a refuge and savior to deliver it from such misery and confusion.

For humanity, the phrase means: God is One, so do not tire yourself with other things. Do not demean yourself and feel obliged to them, or humiliate yourself before them for security. Do not trouble yourself by following them, and do not tremble before them, for the Sovereign of the universe is one and holds the key to and the reins of all things. His command resolves everything. Finding Him means that you obtain whatever you wish and are liberated from interminable indebtedness and innumerable fears.