Why did Paul preach Christ instead of focusing on moral improvement?

In the context of the sermon, Paul’s mission was to preach the gospel in Ephesus, a city rife with idolatry and immorality. Instead of merely moralizing, he proclaimed Christ, believing that true transformation comes through the gospel. As he preached, those who were once idol worshipers were genuinely changed—turning from idols to serve the living God—illustrating that moral improvement is a byproduct of salvation rather than its foundation. The power of the gospel alone is sufficient to change sinners into saints, thereby redirecting their desires and motives.