God created living organisms to go through life cycles. Jesus used these life cycles to illustrate points in many of His parables. Because churches and small groups are living organisms (1 Peter 2:4,5; 1 Corinthians 12:12-31; Ephesians 4:1-16)we would be well served to pay attention to life-cycles when it comes to discussions about 'open' and 'closed' small groups. Close knit communities go through healthy seasons of forming, storming, norming, performing and then sometimes reforming, or if the group slips down the other side of the curve, deforming and death. (For more information about group life cycles, see Small Group Dynamics, Seeds of Change - April 2000)
The question that is repeatedly asked is: "Can the down side of the life-cycle curve be avoided, or is it inevitable?" Can a group, whether a congregation or a small group, stay together, relatively intact, for long periods of time and maintain spiritual health and fruitfulness without new life and renewal being introduced? Can it really be "us four and no more" forever? I have become more and more convinced over the years that a group that is well into its life-cycle together can only sustain spiritual health and consistently experience seasons of renewal and rebirth by being open to new life coming into the group.
This new life can come in many forms: a new group member, a new group mission outside themselves, or the release of members to begin a new mission. To introduce God's new life, the group mission must include being "open" at times.
Periods of small groups being closed can be appropriate. Groups that are focusing on regimented curriculums, discipleship plans, recovery groups, support groups and even leadership training groups could all be legitimately closed ...