How do we know that Christ's message is for everyone?

Paul points out in Ephesians that Christ has broken down the dividing wall between Jews and Gentiles, indicating that His gospel is for all peoples. In Ephesians 2:15, he mentions that Christ abolished the law's commandments that distinguished Jews from Gentiles, creating one new man in Himself. This mystery, hidden for ages, reveals that Gentiles are fellow heirs of the promise in Christ through the gospel, as stated in Ephesians 3:6. Thus, the message of Christ is inclusively universal, extending grace to all who seek Him.