A disciple (μαθητής/manthetes)Is one who engages in learning through instruction from another, pupil, apprentice. And this is always happening whether formally or informally.
Generally speaking, “disciple” was a name given to any follower of a particular teacher.
In the first century, in the known world, there were disciples of many greek philosophers; Epicureanism, fathered by Epicurus, and Stoicism, fathered by Zeno. Paul reasoned with these stoic and epicurean disciples in Athens at the Areopagus ().
Paul, before becoming a Christ follower, was a disciple of Gimiliel ().
John the baptist had disciples until Jesus came on the scene ().
The pharisees question Jesus about his disciples; why they don’t fast but the disciples of the pharisees and John the baptist do ()
The nature of a disciple involves all of one’s being, its a whole person engagement. It’s growing in knowledge through instructional training that leads to attitudinal changes and actions.