Catholic theology
Catholic belief holds that the church exists both on earth and in heaven simultaneously, and thus the Virgin Mary and the saints are alive and part of the living church. Prayers and devotions to Mary and the saints are common practices in Catholic life. These devotions are not worship, since only God is worshiped. The church teaches that the saints "do not cease to intercede with the Father for us. ... So by their fraternal concern is our weakness greatly helped."
Abraham
The Roman Catholic Church calls Abraham "our father in Faith" in the Eucharistic prayer of the Roman Canon, recited during the Mass (see "Abraham in the Catholic liturgy"). He is also commemorated in the calendars of saints of several denominations: on 20 August by the Maronite Church, 28 August in the Coptic Church and the Assyrian Church of the East (with the full office for the latter), and on 9 October by the Roman Catholic Church and the Lutheran Church–Missouri Synod. In the introduction to his 15th-century translation of the Golden Legend's account of Abraham, William Caxton noted that this patriarch's life was read in church on Quinquagesima Sunday.
He is the patron saint of those in the hospitality industry. The Eastern Orthodox Church commemorates him as the "Righteous Forefather Abraham", with two feast days in its liturgical calendar. The first time is on 9 October (for those churches which follow the traditional Julian Calendar, 9 October falls on 22 October of the modern Gregorian Calendar), where he is commemorated together with his nephew "Righteous Lot". The other is on the "Sunday of the Forefathers" (two Sundays before Christmas), when he is commemorated together with other ancestors of Jesus. Abraham is also mentioned in the Divine Liturgy of Saint Basil the Great, just before the Anaphora, and Abraham and Sarah are invoked in the prayers said by the priest over a newly married couple.