I have just started taking a New Testament Greek class. And while learning the Alphabet I see there is no J. So how do they get the letter J in the name of John in the Greek New Testament as in Mark 1:4?
The name “John” is a translation, not the original. The Greek for John is Ioannes, which doesn’t have a J but an I. For the (rare) sound of J, usually appearing in words imported in Greek from other languages, the combination of T and Z is used.