The idea of discipleship is very old. It was common among the Greeks, rarely mentioned in the OT (1 Chron 25:8; Isa 8:16; 50:4), yet a prominent feature of later Judaism. It always involved a teacher-student relationship. Derived as it was from verbs meaning “to learn,” discipleship denoted the learning process but its usage described in addition the necessity of the disciple adopting the philosophy, practices and way of life of his teacher (cf. Xen. Mem. 1. 6. 3). Physical proximity of the student to his teacher was also implied in the meaning of discipleship, although there are instances when its meaning was extended to include pupils separated from their masters by centuries (Dio Chrysostrom 38 . 3-5; John 9:28, where Jews contemporary with Jesus called themselves disciples of Moses).
Discipleship is also a prominent and important concept in the NT. John the Baptist had his disciples (Matt 9:14), the Pharisees theirs (22:16), even Paul his (Acts 9:25).
The word disciple also was used more narrowly, referring to some or all of Jesus’ intimate circle of friends (Matt 10:1; 11:1; Luke 9:54; John 6:8), a frequent synonym for the Twelve.
All of Jesus’ disciples were learners required to “abide” in His word (John 8:31, 32). This meant not only that they were to listen to what He said, but they were also to adopt His teaching as their way of life (Luke 6:40; John 15:7, 8).
His teachings covered many topics, but the whole of it was summarized in one commandment, love (John 13:34); and although discipleship had many facets it was summed up in a single concept—obedience to this command (13:35).
Discipleship was initiated by Jesus (Matt 4:19, an exception being Luke 9:57), and involved a commitment to His person even more than to His teaching. (Note: to criticize Jesus’ disciples was to criticize Jesus, Mark 2:18, 23, 24, and to remove the teacher was to destroy the community of disciples, Mark 14:27, 50.) This is not to say that His disciples were unconcerned with what He taught. They prob. memorized much of His teaching, as was customary for disciples to do, and no doubt were responsible for passing on this teaching as the tradition of the church (1 Cor 15:1-3).
The idea of physical adjacency inherent in the word disciple also applied specifically to Jesus’ associates. It was this idea that placed such radical demands on any one desiring to be His disciple. An itinerant rabbi, Jesus was constantly on the move. To be His disciple was in a literal way to be His follower. (Note: the verb “to follow” occurs about eighty times in the gospels, and exclusively describes the relationship between the earthly Jesus and His companions. It became a synonym for disciple.) This meant, therefore, that every disciple in the strict sense had to leave his occupation (Mark 1:18, 19), his father and mother (10:29), everything (10:28), take up his cross and go forward even to death (Matt 10:38). For the disciple was not above his teacher (10:24), and what would happen to the teacher could also happen to the taught (10:25; Luke 6:40).
The expression “disciple of Jesus,” was also used less strictly. It described those who were His disciples secretly (John 19:38), and by implication those who were not at all physically adjacent to Him (cf. Mark 9:38-40; 5:18, 19). This looser concept of disciple may have made it possible for the writer of Acts to use it as a general term for “Christian” (Acts 9:25 and 19:1 are the only exceptions), the original idea of being an intimate companion of the earthly Jesus now almost forgotten.
Surprisingly, the word “disciple” never appears a single time in the NT outside of the gospels and Acts. It is also instructive to discover that the verb “to follow,” a synonym for disciple and used frequently in the gospels, occurs only twice outside of them to describe the relationship between the risen Lord and His adherents (Rev 14:4; 19:14). Apparently, therefore, because the writers of the epistles saw in the meaning of the words “disciple” and “follower” a disciple-teacher relationship no longer possible in the new era, they dropped them from their vocabulary lest those requirements for the disciples of the earthly Jesus—to leave one’s trade, his father and mother, etc.—be universalized and made general requirements for those who would believe on Him now as the exalted heavenly Lord.
The word “disciple” was revived, however, in the writings of the early sub-apostolic Church, and given much the same meaning as that in Acts, “Christian.” Ignatius, however, employed it almost exclusively to denote those who became martyrs for the sake of Christ (Trallians 5:2; Ephesians 1; 2).
K. H. Rengstorf, μαθητής, G3412, (1942), in G. Kittel’s Theological Dictionary of the NT, tr., and ed. by G. W. Bromiley; E. Schweizer, Lordship and Discipleship (1960); J. J. Vincent, “Discipleship and Synoptic Studies,” Theologische Zeitschrift, XVI (1960), 456-469; S. Legasse, Scribes et disciples de Jésus, RB, LXVIII (1961), 321-345; B. Gerhardsson, Memory and Manuscript (1964).
International Standard Bible Encyclopedia (1915)
(2) We have also the verb, matheteuo, "Jesus’ disciple" (literally, "was discipled to Jesus," Mt 27:57); "Make disciples of all the nations" (the King James Version "teach," Mt 28:19); "had made many disciples" (the King James Version "taught many," Ac 14:21); "every scribe who hath been made a disciple to the kingdom of heaven" (the King James Version "instructed," Mt 13:52). The disciple of Christ today may be described in the words of Farrar, as "one who believes His doctrines, rests upon His sacrifice, imbibes His spirit, and imitates His example."
The Old Testament has neither the term nor the exact idea, though there is a difference between teacher and scholar among David’s singers (1Ch 25:8), and among the prophetic guilds the distinction between the rank and file and the leader (1Sa 19:20; 2Ki 6:5).