Final answer:
Paul delivered a message of salvation and redemption through Christ, which he spread throughout the Greco-Roman world, often challenging societal norms and influencing individuals like Thecla to radically transform their lives.
Step-by-step explanation:
The message that Paul received and delivered to the brethren, as stated in the passages, includes his teachings about a living God who seeks the salvation of men and has sent His own Son for their redemption. Paul preaches the holy works of Christ and encourages living a life of faith, fear of God, and knowledge of holiness. Paul's messages often challenged existing societal norms and promoted the spread of Christianity throughout the Greek and Roman world, which caused discomfort among the Romans due to its radical departure from traditional values.
Furthermore, Paul's interactions with Thecla demonstrate his influence on individuals and their faith-based decisions. Thecla herself exhibited a radical transformation, choosing to abandon her betrothal and follow Paul's teachings, ultimately seeking to spread the word of God herself. These interactions illustrate the profound impact of Paul's messages and the spread of Christianity in the face of Roman societal structures and customs.