THE leader of Scotland's Catholics has denounced the "marginalisation" of Christians for their refusal to endorse lifestyles including homosexuality.

Cardinal Keith O’Brien used his Easter Homily to deliver one of his most vehement attacks on the secularisation of modern society and those who want to “take God from the public sphere”.

The Cardinal is known for his robust defence of traditionalist Christian values but religious commentators said that the sermon constituted his most outspoken attack on secularism to date.

Referring to equality legislation which prevents discrimination against homosexuals, he said Christians faced being sidelined in British society because they were not willing to publicly endorse lifestyles that run contrary to their belief system.

Addressing his congregation at St Mary’s Cathedral in Edinburgh, the Cardinal called on Christians of all denominations to resist the efforts of those who seek to destroy Christian heritage and culture.

He said: “Recently, various Christians in our society were marginalised and prevented from acting in accordance with their beliefs because they were not willing to publicly endorse a particular lifestyle.

“You have only to ask a couple with regard to their bed and breakfast business; certain relationship counsellors; and people who had valiantly fostered children for many years of their particular experiences -- and I am sure they are not exaggerating them.

“Yes, Christians must work toward that full unity for which Christ prayed, but even at this present time Christians must be united in their common awareness of the enemies of the Christian faith in our country, of the power that they are at present exerting, and the need for us to be aware of that right to equality which so many others cry out for.”

However, Dr Evan Harris, a campaigner for the separation of Church and state, branded the Cardinal’s remarks “paranoid and unjustified”.

He said: “It is not ‘aggressive’ to call for an end to religious privilege in society and many people of faith agree with the call for the state to be neutral in religious matters.”

Labour leader Iain Gray described Cardinal O’Brien’s words as a “powerful Easter reminder of the role that faith has played in Scotland’s past and present” but called for an equal platform for all faiths and none.

An aide to First Minister Alex Salmond said: “The Catholic Church and all of Scotland’s faith groups play a vital role in Scotland’s national life, and the Cardinal advocates Christian beliefs on that basis, as he is entitled.”

An aide to Scottish Liberal Democrat leader Tavish Scott said: “All faiths and those who don’t follow a faith should be respected equally.

“Discrimination of any kind should not be tolerated in a modern Scotland.”

Pope Benedict XVI used his Easter Sunday message to call for peace in the Middle East and an end to fighting in Libya.

The Catholic Archbishop of Westminster, the Most Reverend Vincent Nichols, spoke in his Easter message of his hopes for peace in countries hit by conflict such as Libya, Syria, Afghanistan and Ivory Coast.