Some might say: “I don’t need to officially become a member to commit to my local church.”
However, the 1st-century church practiced measurable membership.
For mutual affirmation
Baptism was the official act of mutual commitment for new believers (Acts 2:41; 16:31-33; 18:8; 19:5; Matt 28:18-20).
A letter of commendation was the official way of affirming “member transfers” (Acts 15:23-27; 18:27; Eph 6:21).
Church Membership: The mutual affirmation of faith and commitment between a Christian and a local church.
Church Membership: The public announcement that a local church will accept and disciple a Christian and that Christian will accept and be discipled by that local church.
For meaningful care
Pastors knew the specific congregations they led (Acts 20:28).
Congregations knew the specific pastors they followed (Heb 13:17).
Congregations knew who was under church discipline (1 Cor 5:12-13; cf. 1 Cor 5:4; 2 Cor 2:6; Acts 2:41; Mt 16:31-33; 19:5; cf. 18:18-20).
The 1st century church kept countable lists.
Widows included in “the number” (1 Tim 5:9)
The 3000 people “added” (Acts 2:41)
Not all attendees were Christians (1 Cor 14:23-24)
Specific covenant care
Old Covenant: lists were God’s way of saying, “I know you by name.”
New Covenant: lists are the same. God’s specific care does not end in the new covenant. He leaves the 99 to find the one.
“Christians were never meant to declare themselves followers of Christ apart from the church.”