How do we know Paul's actions in the temple were wrong?

Paul's actions in the temple, particularly participating in the Nazarite vow and the associated sacrifices, represented a significant departure from the core message of the gospel. The preaching of Paul emphasized that salvation is through Christ alone and not through law-keeping or rituals (Ephesians 2:8-9). By engaging in temple practices that had been fulfilled in Christ's death and resurrection, Paul was not only denying the sufficiency of Christ’s sacrifice but also creating confusion about the nature of salvation. His actions were a capitulation to pressures from others and a temporary lapse into legality, demonstrating that even great men of God can err. Paul’s situation serves as a reminder to resist the temptation to revert to works for righteousness.