What is one of the themes of William Blake's poem "The Tyger?"

One theme of
Blake's poem is the mystery of how a God that could create a creature as gentle as a lamband
identify the lamb with his son, Jesuscould also make a creature as fearful and bloodthirsty as a
tiger.

The poem thus explores two sides of God. One side is gentle,
comforting, and invitinglike a lamb. The other is sublime: it strikes us with fear and
awe.

The tiger, because of the fear it raises in us, is an example of the
sublime. The sublime, usually associated with nature, includes those elements of the natural
world that are both beautiful and yet fill us with a sense of God's grandeur and vast might.
Mighty waterfalls crashing down or the view from icy mountain tops could fill us with a sense of
awe and terror. So does Blake's tiger.

In the poem, the speaker wonders why
God is both so gentle as to create the lamb and so terrifying as to create a dangerous predator.
The poem dwells in the space of mystery, not offering answers but asking
questions.