What is the paradox explored by William Blake in his poem "The Tyger?"

Thein
"" is framed in a series of questions which the speaker asks the tyger. Simply put,
the paradox is how a loving, all-knowing God, who makes things so wonderful and innocent as the
Lamb (referring to the animal and Jesus Christ), could also make something as terrible and
ferocious as the tyger (I'm keeping Blake's spelling). 

Blake
was...