Pope Benedict XVI is set to lead Easter Sunday Mass in Rome's St Peter's Square and deliver his traditional Easter message from the basilica's balcony. At a vigil Mass on Saturday evening, he voiced fears that mankind is "groping in the darkness, unable to distinguish good from evil". The theme of his homily was the contrast between darkness and light. The ceremony was brought forward from its traditional midnight start in order not to tax the 84-year-old's strength. He was wheeled on a raised mobile platform along the central nave of a darkened St Peter's Basilica carrying a single lighted candle, symbolising the resurrection of Jesus Christ. Gradually, as other believers lit their individual candles from a single flame, St Peter's was flooded with light, the BBC's David Willey reports from Rome. "The darkness enshrouding God and obscuring values is the real threat to our existence and to the world in general," the Pope said. "If God and moral values, the difference between good and evil, remain in darkness, then all other lights, that put such incredible technical feats within our reach, are not only progress but also dangerous, which put us and the world at risk." During the Mass, the Pope also baptised eight new converts by pouring water over their bowed heads. The pontiff's official schedule - which recently saw him return from visits to Cuba and Mexico - is taking a toll, our correspondent says. His elder brother has said in Germany that Pope Benedict - who turns 85 later this month - intends to cut back on foreign travel, as it wears him out. Easter is one of the most joyous celebrations in the Christian calendar, marking the crucifixion and resurrection of Jesus.