BARCELONA, Spain — Pope Leo XIV will hold Mass at Barcelona’s iconic La Sagrada Familia on Wednesday where he will offer a papal blessing to the highest spire of what is now the tallest church in the world. Sagrada Familia’s distinctive Modernist basilica has been under construction for more than 140 years but, in February, work finally finished on the central Tower of Jesus Christ, which stands at 566 feet high and is crowned with a gigantic five-story ceramic cross. The Mass in Barcelona will