Paul draws his second letter to a close with the simple instruction: 'Test yourselves'. How do you measure up? How is your own faith in Jesus?
Yet he then gives no checklist or spiritual MOT specification. Instead its just 'you relate to Christ, so where are you in your relationship?'. Paul wants followers of Christ, not Paul-clones!
The concept here is to take responsibility for your own discipleship. Any Christian reaching maturity in their faith should do this. That means being up for self-testing, and finding resources (er, this blog?) and people you can do this with. It also means deliberately being open and honest with perhaps one or two trusted individuals, allowing reflection and people to ask you probing questions. Perhaps more importantly it also means giving them permission to prod you later on how you are doing.
Ultimately it means not hiding, but allowing Jesus to illuminate areas in your life that need attention through another person. That other person will be supportive, will pray with you, and walk the journey with you. Sometimes this is like a student-mentor scenario, but it could also be two or three mutually helping each other.
Discipleship for Paul wasn't simply for himself - it was for others. All the time he rooted for the truth to unfold in others (v8), looking to build others up (v10). Paul was all about pointing others to Christ, so that they could be those who learn direct from God the Father (see John 6:44 - 45) and follow Christ for themselves. The failure for Paul, if any, would be for people not to discover and stick with Christ. He is therefore keen that people encounter Christ and persist in lifelong discipleship!
Through both letters we have consistently seen Paul lowering himself so that others may be raised up to Christ. He could have steadily built 'the church of Paul' as he travelled and evangelised, but no, he would rather sink out of sight leaving people to stand for themselves before the risen Lord.
That same responsibility is for us too: to be growing ourselves, and leading others to the point where they can maturely take responsibility for their discipleship. Hence the key question/challenge:
Key Qn: [OUT] Does your discipleship help bring others towards Jesus Christ?
Key Challenge: Talk through your own discipleship with another person
Take the challenge either way (or both!): either discussing with another Christian to allow illumination into your own life, or get alongside someone less far forward in faith to shine into their life.