The first element (and most obvious) of Paul’s discipleship method is Gospel-infused instruction to selected individuals and churches. In Acts 20, Paul tells the Ephesian elders that he had no regrets concerning his time among them because he “had not shunned declaring unto them the whole counsel of God.” One of Paul’s disciple-making tools was instructing new believers in Gospel growth and potential leaders such as Timothy and Titus in practical matters of church, disciple-making, family matters, finances, work ethic, social order and civic duty. All of this instruction is premised upon and infused with Gospel intentionality. Legalism and moralism remove or isolate the objective and propositional teachings of Scripture from the Gospel. You will find no incidence in Paul’s writing, or narratives of Paul’s ministry in Acts, where he instructs believers without firmly asserting the Gospel of grace as the impetus for action or behaviors that diminish self and exalt Christ. Grace saturated morality is Gospel-initiated behavior. Rules do not a disciple make.
For an example of Paul’s teachings to new believers, read Romans. The book of Romans is the centerpiece of salvation theology in the NT and its first eight chapters are an incredible treatise on the mechanics of the Gospel. The last eight chapters explain practical matters of God’s plan and purpose for the redeemed while on earth. All of it premised upon the first 8 chapters. Read the first three chapters of Ephesians to get some grasp of how the Gospel gives us a new identity then read the last three chapters to understand how this new identity practically applies to our daily lives.
There is no good reason to assume that Paul didn’t approach one on one discipleship in the same manner. We know that Timothy and Titus received theological and practical instruction as they grew into young pastors. All of this instruction comes within a very personal and caring relationship that tolerated failures, extended grace, forgave weaknesses, lovingly confronted, instructed in a timely manner and dominated Paul’s prayer life.
We will not write new books into the NT canon but we can write Gospel-infused letters to growing young believers. We can sit across the table from these young believers and hear their story, keep them centered on the cross, grace and the Gospel. We can challenge their behavior by comparing it to the Gospel rather than our moral expectations. The vehicle of Paul’s discipleship method was a personable, approachable and hands-on, gritty style but Gospel-infused instruction was the substance. Paul’s authentic relationships, winsome way and co-laboring leadership paradigm are good and beneficial but it would not be biblical discipleship without Gospel-infused instruction whether by word or deed.