Follow-up is an action word, an attempt to translate some theological imperatives of the Scriptures into something we can actually do.

Briefly defined, follow-up is the process of helping a new or young Christian to grow and mature in his faith. We could call it a “sanctification assistance program.”
There are three basic reasons for follow-up, centering around a command, a responsibility, and a need.

The Command to Be Good Shepherds

When Jesus first called his disciples, he called them to become fishers of men (Matthew 4:19)—to reconcile people to God. But in John 21:15-17, where the call deepens into a commission, his metaphor changes from fish (non-Christians) to sheep (Christians). His followers must not only reconcile non-Christian men and women to God, but must then spiritually build up these new believers.
Simon Peter’s threefold denial of Christ demanded the threefold assertion of his love in John 21. And the practical proof of this love, Jesus told him, was to “feed my sheep.” Peter later expressed his concern for this task in 1 Peter 5:2-4, teaching shepherds of the church to serve willingly and to set good examples in their follow-up.

In the Great Commission recorded in Matthew 28:19-20, Jesus commands us to “make disciples of all nations”—not only winning them to Christ, but helping them become committed and effective followers of Christ. Of course, we must be disciples ourselves before making disciples of others.

The Responsibility of Spiritual Parents

Paul told the Corinthians that he cared for them because “in Christ Jesus I became your father through the gospel” (1 Corinthians 4:15). In this passage Paul distinguished between spiritual guardians and a spiritual father, indicating that a spiritual father has the greater concern for the children. In Job 39:16 the Lord speaks disparagingly of the ostrich that “treats her young harshly, as if they were not hers.” Parenthood should mean true concern for the offspring.

But today we see many spiritual orphans who have never experienced sufficient love, guidance, and self-sacrificing help from their spiritual parents during the formative years of their spiritual childhood.

The Need of Spiritual Children

Infants in Christ must be fed—not with theological and ecclesiastical jargon, but with milk (1 Corinthians 3:1-2)—the simple truths pertaining to salvation, God’s word, prayer, and fellowship in the church. At first this must be spoon-feeding, but it should later become pasture-feeding. We would hardly expect a mature Christian to depend for his spiritual food on sermons, either spoken or written. In the process of growing he should be taught how to study the Bible for himself.

Spiritual infants must also be protected, especially from Satan, who “prowls around like a roaring lion looking for someone to devour” (1 Peter 5:8). Younger Christians are the most susceptible to his attacks, so they must be regularly prayed for, and equipped with their own basic defense techniques such as prayer faith, and the knowledge of God’s promises.

Finally, spiritual infants must be taught. Paul’s practice in follow-up was “admonishing and teaching everyone with all wisdom, so that we may present everyone perfect in Christ” (Colossians 1:28). Young Christians should learn how to be able on their own to eat (study the Bible), to walk (make progress in following God’s will), and to talk (share their faith naturally with others).

In the Great Commission, Jesus did not say our task with others was simply teaching them everything he had said, but “teaching them to obey everything” (Matthew 28:10). Without learning obedience their Christian lives would degenerate into the lukewarmness which Christ abhors (Revelation 3:15-16).