“For our boast is this, the testimony of our conscience, that we behaved in the world with simplicity and godly sincerity …” (v12). When Paul and other leaders faced criticism from the churches, they said that their “testimony” was their own lives. They paired words about Jesus with “simplicity and godly sincerity,” lives marked by the love and compassion they had themselves received from Jesus. They were open about the hardships they endured, and they spoke about God’s comfort and strength from experience.
“It is God who establishes us with you in Christ …” (v21). Godly leaders are spiritual brothers and sisters, willing to share their lives, willing to walk together in Christ.