Lord Jesus commanded the gospel of the Kingdom to be preached and that the apostles should make disciples (Matthew 28:19). Every Christian should also be a disciple. I don't know how it is possible to be a Christian in reality and not be a disciple. I don't know how you arrive at your conclusion that not everyone was expected to be a disciple. Acts 4 recounts the experience of the early church:
"42They devoted themselves to the apostles’ teaching and to the fellowship, to the breaking of bread and to prayer.
43A sense of awe came over everyone, and the apostles performed many wonders and signs.
44All the believers were together and had everything in common.
45Selling their possessions and goods, they shared with anyone who was in need.
46With one accord they continued to meet daily in the temple courts and to break bread from house to house, sharing their meals with gladness and sincerity of heart,
47praising God and enjoying the favour of all the people. And the Lord added to their number daily those who were being saved."
"All the believers................"