The Roman and Eastern Orthodox Catholic Churches provide crucifixes, icons, murals, statues and symbols as visual aids for prayer, meditation, contemplation and recollection. Just as pictures of departed family members and friends placed on walls and shelves serve to remind us of our love for them, and may evoke prayers for them, so does an object of religious subjects or persons prompt thoughts and memories.
Praying the rosary of the Blessed Virgin Mary consists of six Our Father and 53 Hail Mary in four groups: Joyful, Sorrowful, Glorious and Luminous. These cover events in the lives and deaths of Jesus and Mary, and are assigned to different days of the week. Visual reminders of the particular series of prayers help in staying focused. The more focused, the more fruitful the prayers.
Catholics worship only the Three Persons in the Holy Trinity. Everything else is a visual aid.