Theastical or Theistical: How To spell?

The word Theastical is misspelled against Theistical, an adjective meaning "pertaining to theism, a theist; accding to the doctrine theists."

Word contains consecutive vowels 'EI' in between alphabets th & stical is misspelled as 'EA'
Wrong Spelling:  th-ea-stical 
Correct Spelling:  th-ei-stical 
Find more wrongly spelled words of Theistical to spell it well.