Acts 16:31 - Ellicott's Commentary On The Whole Bible

And they said, Believe on the Lord Jesus Christ. — The plural pronoun is not without significance. St. Paul was not the only teacher. Silvanus also took part in the work of conversion. The words have naturally become, as it were, the crucial instance — standing nearly on the same level as that of the penitent robber on the cross — of the conditions of salvation. To believe in Christ, with all that this faith involved, was to obtain salvation, i.e., deliverance from sin, and not only from the penalty of sin, in this world and in the world to come. The Greek presents a contrast which is lost in the English. He had called them by the usual title of respect, Kyrii (= Sirs, or Lords); they answer that there is one Kyrios, the Lord Jesus Christ, who alone can save.