The world's most followed religion is changing rapidly. Hannah Ajala explores how church bells travelling from Italy to Nigeria herald Africa's new role as the beating heart of Christianity. The Marinelli family in Italy have been making church bells for nearly 1,000 years. But in recent decades demand from Italy has fallen as faith dwindles, whilst orders from sub-Saharan Africa have grown dramatically. Hannah Ajala follows the journey of the Marinelli bells to Nigeria where she interviews one of the country's most famous pastors, Dr Paul Enenche, about the rapid rise of Pentecostalism.