One of Ireland’s leading theologians has accused the leader of the 1916 Easter Rising against British rule of using Catholicism in an unchristian way to attract people to the cause.

As Ireland prepares for the 100th anniversary of the uprising this Easter Sunday, the Jesuit intellectual Father Seamus Murphy has launched a blistering attack on the morality of the revolt and those behind it.

Murphy said leader Patrick Pearse’s portrayal of the rebellion as a sacrifice “might masquerade in Catholic devotional dress, but its meaning, the master who it served, was not the Christian God”.

Writing in the spring edition of the Jesuit journal Studies, Murphy is the first major Irish religious figure to launch a blistering attack on the Rising’s legacy.

Unionists in Northern Ireland are boycotting the centenary, which will climax with a march through Dublin city centre on Easter Sunday morning. Meanwhile some Irish republic-based writers have warned that hardline dissident republicans opposed to the peace process will exploit the commemorations and recruit a new generation of fighters.

In his article, Murphy accuses Pearse of using and abusing “ordinary Irish Catholics’ reverence for the sacrifice of the Catholic mass, and their spiritual openness (or ‘vulnerability’) to its symbols”.

The associate professor of philosophy at Loyola University Chicago, and one of Irish Catholicism’s leading intellectuals, said: “Pearse, familiar with but not overpious about, his Catholicism, uses the Old Testament and scapegoat themes, but NOT with Christian meaning.

“However, since all this superficially resembles some Catholic mass themes, he is able to channel the Catholic energy that is out there among ordinary Irish Catholics in the direction of a violent bloody undemocratic and intolerant nationalism. It’s very clever.”

A poet and teacher, Pearse was the leader of the rebellion and read out the proclamation the rebels declared for independence on the first day of the rising at the revolt’s HQ – the General Post Office in what is now Dublin’s O’Connell Street. All seven signatories of the proclamation in Easter 1916 who surrendered to the British were executed in May of that year.

While the rebellion had minimal support in Easter week 1916 with thousands of Dubliners fighting in British regiments on the western front in Europe, the execution of Pearse and his comrades generated enormous sympathy to the republican cause. Pearse himself saw their deaths as a Christlike sacrifice that would, through blood, create a new nation.

Critics of the current centenary, such as Murphy, believe that uncritical coverage of the Rising’s legacy will enable republican hardliners to argue in the 21st century that there is “unfinished business” over 1916 – Northern Ireland remains within the UK due to its unionist majority.

Referring to Pearse’s own writings, Murphy added: “In the preface to his [work] Ghosts, Pearse remarked, ‘There is only one way to appease a ghost. You must do the thing it asks you.’ The command of Pearse’s ghost had been obeyed in this centenary of the Rising, and his bloody sacrifice re-enacted sacramentally. It will not be without effect.”

Meanwhile, Ireland’s president, Michael Higgins, has issued a pre-Easter statement in which he hopes the centenary will not be a cause for further divisions. Higgins admitted that the centenary was one of “ethical sensitivity”, especially in Northern Ireland.

He said: “My great hope, as head of state, is that we will put ourselves into each other’s history. We must be able to take your version, my version, move into the shoes of the other, and we must be open to changing our versions as new facts, information and analysis become available to us.

“I would hope that people in Northern Ireland will approach these commemorations, and as we commemorate the [Battle of the] Somme, that we’d be able to do so generously.” But Higgins stated that when questions are raised about the morality of the violent uprising, people should remember the historical context at the time.

“When we decide to address the issue of violence, let us speak of the violence of empire, the violence of state, the violence of insurrection.”

More than 3,500 members of Ireland’s defence forces will take part in the main commemorative parade through the centre of Dublin when they will file past the GPO and take the salute from Higgins. Sinn Féin and the republican dissident groups are holding separate, rival commemorations across Ireland on Sunday.

Ahead of the main official parade, the Irish culture minister Heather Humphreys said it would be the biggest-ever march in the country’s history. “The 1916 Rising was the seminal moment in our history, which set Ireland on the path to independence,” she said.

“This weekend, we will respectfully remember all of those who lost their lives; those who took brave and fateful decisions, and those who simply got caught up in the conflict. The weekend’s events are rooted in respectful commemorations.”