The veneration of the saints, and pre-eminently of Mary the mother of Jesus, is a major devotional practice of the Roman Catholic and Orthodox churches, in which the holy men and women of the faith are honoured, taken as examples, and asked to pray to God on behalf of the living. The practice rests on the belief in the "communion of saints", that the church embraces both the living and the dead in Christ, and that those who have died in holiness are alive with God and can intercede for those still on earth. As with icons, the tradition draws a firm theological line: the saints are venerated, honoured as friends of God and asked for their prayers, while worship is reserved for God alone. Mary, as the mother of the Lord, receives the highest veneration among the saints, though still categorically less than the worship due to God.
In practice this devotion fills the calendar and the landscape of Catholic and Orthodox life: saints' days commemorate the holy ones through the year, churches and persons take saints as patrons, relics are honoured, and countless prayers ask particular saints to intercede for particular needs. Marian devotion is especially rich, expressed in prayers such as the Hail Mary and the Rosary, in feasts, apparitions and pilgrimages, and in the many titles under which Mary is invoked. The Protestant Reformers largely rejected the invocation of saints as unwarranted by scripture and as obscuring the sole mediation of Christ, and the practice remains one of the sharpest divisions between Catholic and Orthodox Christianity on the one hand and most of Protestantism on the other, a difference less about honouring holy examples, which most Christians accept, than about whether the departed saints may and should be asked to pray for those on earth.