Cyprian of Carthage, Three Books of Testimonies Against the Jews III.45: That believers who differ among themselves ought not to refer to a Gentile judge

In the first Epistle of Paul to the Corinthians: “Dares any of you, having a matter against another, to discuss it among the unrighteous, and not among the saints? Know ye not that the saints shall judge this world?” And again: “Now indeed there is altogether a fault among you, because ye have judgments one against another. Wherefore do ye not rather suffer injury? or wherefore are ye not rather defrauded? But ye do wrong, and defraud, and this your brethren. Know ye not that the unrighteous shall not obtain the kingdom of God?”