The book of Acts presents a vivid and inspiring picture of discipleship in the church. The early church was a community of disciples. We see the gospel message proclaimed in various venues by disciples who call people to repent, believe, and be baptized into the fellowship of the church. But it doesn’t stop there. Once in the church, converts are to devote themselves “to the apostles’ teaching [about Jesus] and the fellowship, to the breaking of bread and the prayers” (Acts 2:42). This is essential for maturing in discipleship with Jesus, who is now present through the Holy Spirit. Interestingly, these four elements, which were at the heart of church life in Acts 2:42 were also at the heart of Jesus’ discipling of the twelve.
The most common word for people who came to saving faith in Jesus in the early church is disciple. In other words, those who were saved in Jerusalem at Pentecost and throughout the Roman Empire for years afterward understood themselves to have become disciples of Jesus, like those who had become His disciples during His earthly ministry. Here are just a few examples (italics mine).
Now in the days when the disciples were increasing in number, a complaint by the Hellenists arose against the Hebrews because their widows were being neglected in the daily distribution. And the twelve summoned the full number of the disciples and said . . .
And the word of God continued to increase, and the number of disciples multiplied greatly in Jerusalem. (Acts 6:1–2, 7)
But Paul, still breathing threats and murder against the disciples of the Lord . . .” (Acts 9:1)
For some days he [Paul] was with the disciples at Damascus. (Acts 9:19)
Now there was in Joppa a disciple named Tabitha, which, translated, means Dorcas. (Acts 9:36)
And in Antioch the disciples were first called Christians. (Acts 11:26)
So the disciples determined, everyone accordingly to his ability, to send relief to the brothers living in Judea. (Acts 11:29)
But Jews came from Antioch and Iconium, having persuaded the crowds, they stoned Paul and dragged him out of the city, supposing that he was dead. But when the disciples gathered about him, he rose up and entered the city, and on the next day he went on with Barnabas to Derbe. When they had preached the gospel to that city and had made many disciples, they returned to Lystra and to Iconium and to Antioch, strengthening the souls of the disciples, encouraging them to continue in the faith, and saying that through many tribulations we must enter the kingdom of God. (Acts 14:19–22)
Clearly the people referred to as disciples in these passages are not a special highly committed type of Christian; they are ordinary believers. Summarizing, Michael Wilkins says,