I don't believe in Odin or Jupiter; I regard them as creations of ancient mythology. Am I professing faith?
I don’t believe in Odin or Jupiter
Then no is the answer to your previous question (Is it professing faith if I say Man created Odin, or Man created Jupiter?) given that by created you meant brought into actual existence. However, you subsequently wrote:
I regard them as creations of ancient mythology. Am I professing faith?
That indicates that by created you did not mean brought into actual existence and instead you meant developed as an idea or concept or something like that, and again the answer depends on why you regard them as creations of ancient mythology.
For example, if your regard is based on evidence you have seen precluding the necessity of faith, then the answer is no to either of your questions about professing faith.
For another example, if your regard is based on the word of others who have led you to that regard without particular evidence, necessitating at least faith in those others, then the answer is yes to either of your questions about professing faith.