John Paul II's letter on the Rosary says the first half of the Hail Mary is "drawn from the words spoken to Mary by the Angel Gabriel and by Saint Elizabeth," and that the name of Jesus is its "centre of gravity." The repetition is meant to work the way a refrain does, holding the attention steady while the mind stays on an event in the Gospel. The same letter, quoting St. Paul VI, admits the danger the objection points to: without contemplation the Rosary "runs the risk of becoming a mechanical repetition of formulas." The second half of the Hail Mary ("pray for us sinners") is a request for Mary's prayers, which rests on a different question, answered separately. The Rosary is a devotion, not an obligation; no Catholic is required to pray it, and a guest on a pilgrimage may simply listen.
Faith & pilgrimage · YOUR QUESTION, ANSWERED
Is the Rosary biblical, or is it "vain repetition"?
The Rosary is not found in the Bible as a prayer form, but it is built largely from the Bible: the Our Father, the greetings of the angel Gabriel and of Elizabeth to Mary in Luke 1, and twenty mysteries, scenes from the lives of Christ and his mother, most of them taken straight from the Gospels, to think about while praying. In Matthew 6:7 Jesus warns against empty, mechanical prayer, not against repeating words; he teaches the Our Father immediately afterwards and repeats his own prayer in Gethsemane (Mark 14:39). St. John Paul II described the Rosary as "at heart a Christocentric prayer."

Related questions, answered
Where is the Hail Mary in the Bible?
Its first half joins two verses of St. Luke's Gospel: Gabriel's greeting to Mary (Luke 1:28) and Elizabeth's (Luke 1:42). The second half, asking Mary to pray for us, is a later prayer of the Church.
Can a Protestant pray the Rosary?
Yes. Nothing prevents it, and some do. A Christian uneasy about asking Mary's prayers can pray the Our Father and meditate on the Gospel scenes, which are the heart of the Rosary.
Do Catholics have to pray the Rosary?
No. It is a devotion the Church warmly recommends, not a requirement. On most Catholic group pilgrimages it is prayed together at some point in the day, and anyone may sit it out.
This question may be part of your discernment
- Catholic Curious PilgrimageA Catholic pilgrimage made as an honest guest: a way for someone who is not Catholic, or not sure, to see the Catholic faith where it is lived and prayed, with every practice explained plainly and no pressure to become anything.
- Our Lady / Rosary PilgrimageA Rosary pilgrimage is a journey to the places where the Church learned to pray the Rosary, made in order to contemplate the life of Jesus Christ with His Mother and to bring that prayer home.
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