“Thus St. Augustine clearly proves, that Christians are true Israelites, not according to the flesh, but according to the Spirit; and that thereby they are heirs of the land of promise, which is in heaven. Wherefore, the gates of the heavenly Jerusalem have inscribed on them the names of the twelve tribes of Israel, because the gate by which we enter the land of promise is the inheritance of the Sons of God, who alone are true and sincere Christians, the children of the blessed Apostles. These are signified by the true Israelites, that is, the sons of the patriarch Jacob; and when St. John adds, that on the gates were twelve angels, he means that angels are the guardians of those gates, whose office is to prevent any one entering, that has not the right of inheritance. For this reason, perhaps, St. Michael, the archangel, is represented with scales in his hands, because by the angels under him he examines the merits of those who aspire to this heavenly city.” -St. Robert Bellarmine, “On the Eternal Happiness of the Saints”, Bk. 2, Ch 10