Old crypogram

You have found an old ciphertext, where you know that the plaintext discusses a biblical subject. You just finished your first classes in the topics of cryptography. Therefore, it’s time to test yourself.

Make use of the new skills and try to find out what is in the back of the cryptogram. You will know if the decryption is good if you get the correct SHA- digest of the text, in hex (the flag).  The old cryptogram is the sub_ciphertext.txt.

Your task is to find the key and the plaintext