Closely related to the theme of religion, awe and amazement are what the divine or sublime inspire. The sublime is a specific term that used to mean more than it does today. Now, you can say a bowl of ice cream is "just sublime," but back in the day (say, late 18th century England), people would have no idea what you meant. To them, the sublime is (typically) big, scary, mysterious, awe-inspiring, and, yes, amazing. You could get published writing a book about how "The Tyger" is about the sublime – Fearful Symmetry is in fact the title of one of the most influential books about Blake's poetry. The sublime is big and unable to be "framed." It’s scary and "fearful," full of "deadly terrors." It’s mysterious, lurking in the "forests of the night," forcing you to put thirteen question marks in your poem. It is awe-inspiring and amazing. Thus, "The Tyger" is in part about the fact that it is mysterious. It is about the awe and amazement that such mystery and sublimity inspires.
The awe and amazement the speaker has for the Tyger is the same awe and amazement he has for the divinely-inspired poet.
The language of Blake’s poem is representative of the speechlessness of a person confronted by the power of the sublime.