The Archbishop of Westminster has hailed Easter as a "triumph of light over darkness and life over death".
In his Easter Vigil at Westminster Cathedral, the Catholic leader of England and Wales called for for believers to live their faith with a "young heart".
Vincent Nichols said: "This week, Pope Francis spoke of its reality in these words: 'Look around - how many wounds are inflicted upon humanity by evil.
"Wars, violence, economic conflicts that hit the weakest, greed for money which none of us can take with us.'
"We know how those habits become actions, acts which we regret yet often repeat. All of this comes under the uncomfortable word 'sin'.
"All of this is overcome in the victory of Christ."
More top news
Mladic, now 75, was the military commander of Bosnian Serb forces in the 1990s, who fought against the Bosnian Croat and Bosniak armies.
Weather: Heavy rain and strong winds in the north
His representatives said Cassidy, who was hospitalised last week, died "surrounded by those he loved."