Is it true that the rosary came from pagan practice, as Iglesia ni Cristo claims?
Far from being a pagan thing, the rosary is about the life of Jesus and his Mother's place in it. The Hail Mary is all about his incarnation.
On October 7, 1571, Pope St. Pius V equipped all the sailors of the fleet of the Holy League (a coalition of European Catholic maritime states) with rosaries, and they prayed them. As a result, they inflicted a major defeat on the Ottoman Empire and thereby saved Europe from a Muslim takeover.
The Iglesia ni Christo was founded on July 17, 1914, 343 years later. It helps to know history.