2 Corinthians 3
What gives you confidence? Can you think of a time in your life when at first you lacked confidence, and then something changed so that you became confident? What changed?
Do you think Christians ought to be confident people? In what way? What about all those passages that seem to say we shouldn't be proud?
Paul was sometimes accused by his opponents of being proud. In fact, sometimes he still is! Read this short passage where he defends his 'confidence'.
Read 2 Corinthians 3:1-6
Do you think this passage makes Paul seem proud?
What do you think Paul means when he says that the Corinthian church are 'our letter of recommendation from Christ'?
What defence does Paul give for his confidence?
What do you think he means by "the letter kills, but the Spirit gives life"? 
Paul spends the rest of this chapter expanding on the contrast between the Law given through Moses in Exodus, and the Spirit given by Jesus in the New Testament.
Before reading the rest of 2 Corinthians 3, watch this video from the Bible Project explaining what is meant by 'the Law' and how it relates to the Spirit:
Read 2 Corinthians 3:7-18 
What are all the contrasts Paul describes between 'the ministry of Moses' and 'the ministry of the Spirit'?
How does the ministry of the Spirit give confidence?
How does the ministry of the Spirit transform us?
Do you have a testimony of the transformative work of the Spirit in your own life? How has the Spirit been helping you to become a better person by changing your heart?
Spend some time praying that the Holy Spirit would change your heart, that you might be "transformed into his image with ever-increasing glory".
 "How can Paul say that the written code kills? The answer seems to be that the written code (the law) kills when it is used improperly, i.e. as a set of rules to be observed in order to establish one’s own righteousness (cf. Rom. 3:20; 10:1–4). To use the law in this way inevitably leads to death, for no-one can satisfy its demands, and therefore all come under its condemnation. So a ministry of the written code in this sense is a ministry of death. However, the ministry of the Spirit is quite different. It is a ministry of the new covenant under which sins are forgiven and remembered no more, and people are motivated and enabled by the Spirit to do what the improper application of the law could never achieve (cf. Jer. 31:31–34; Ezek. 36:25–27; Rom. 8:3–4)."
Colin G. Kruse, 2 Corinthians: An Introduction and Commentary, p93
 You might also like to read Exodus 34 to better understand the events Paul is referring to in this chapter.