According to American Heritage: “Of, relating to, or in accordance with the Christian gospel, especially one of the four gospel books of the New Testament.”
According to Oxford: “evangelist • noun 1 a person who seeks to convert others to the Christian faith. 2 the writer of one of the four Gospels. 3 a passionate advocate of something. ”

( It is interesting to note that American dictionaries have pages of words with slightly different meanings derived from the root “evangelist”, almost none of which are recognized by Oxford. )

Now, I have read the bible, though not thoroughly and certainly can’t claim to have studied it… but I can’t seem to recall the chapter on physics. I must have missed that part 😉