CAIRO — As Egypt’s freshly elected president, Mohammed Morsi, arrived Monday at the presidential palace that for 31 years was occupied by Hosni Mubarak and cordoned off by his guards, some Egyptians were openly worried about how closely the new head of state would adhere to the Islamist views espoused by his movement, the Muslim Brotherhood.

A day after Morsi fulfilled a campaign promise and resigned from the Brotherhood and its political arm – saying he wanted to represent all Egyptians – critics were skeptical of the move, wondering whether Morsi would still serve as the front man for the 83-year-old organization’s hard-line religious teachings.

“He has resigned on paper but did not and will never resign ideologically,” said Hanan Fikry, a Coptic Christian activist and author. “It takes people decades of ideological revisions to cut loose from entities they once swore allegiance to.”

Morsi began assembling his team of advisers Monday and will confront serious challenges once he’s sworn in July 1 – chiefly a potential confrontation with the powerful generals who are ruling the country on an interim basis and hold most of the country’s political power, including supervising the process of drafting a new constitution. He also has to win over Egyptians who question his nationalist credentials, despite remarks he made Sunday night calling for national unity following a divisive presidential race.

Fikry believes that Morsi “is a Brotherhood candidate who obeyed the Islamist movement’s will” by stepping in to the presidential campaign after Khairat el Shater, the Brotherhood’s strategist, financier and first choice for president, was disqualified from the race because of a political ban dating from the Mubarak era.

In 1977, Morsi, like all who join the Brotherhood, swore an oath of loyalty to the movement, which was banned at the time, and its chairman, or supreme guide. Fikry said she was concerned that Morsi’s win, officially announced Sunday, represents a threat to Egypt’s identity as a secular state.

“The question will be answered through the constitution. If it does not satisfy sensitive issues such as religious freedoms and minorities, large portions of the population will be having a standoff with him,” said Fikry, who writes for the Cairo-based Coptic journal Watani, and heads a nongovernmental group called One Nation for Development and Freedoms.

The ascendance of Morsi, the first Islamist ever elected to lead an Arab country, has also led Fikry to change how she identifies herself.

“I used to be an activist, but since Morsi was declared president, I proudly introduce myself as a female, Coptic activist,” she said.

Such concerns were voiced not only by Coptic Christians like Fikry – the group makes up about 10 percent of Egypt’s population – but also by those who identify themselves with the revolutionary movements that helped lead the charge to oust Mubarak last winter. Some revolutionary figures, who once stood shoulder to shoulder with the Muslim Brotherhood in the massive anti-Mubarak demonstrations in Cairo’s Tahrir Square, decided to endorse Morsi’s competitor, former Mubarak prime minister Ahmed Shafik, to fight what they described as “Islamists erasing Egypt’s civil identity.”

“Morsi will never quit the Muslim Brotherhood because this religious organization is a part of his belief,” said Mohamed Abu Hamed, an independent member of Parliament, which was recently dissolved by the constitutional court.

Abu Hamed, who was harshly criticized by revolutionary groups for endorsing Shafik, said he will “put Morsi to the constitutional test.”

“If he adopts a constitution that upholds the principles of a civil, democratic state, then he did resign the Muslim Brotherhood and I will support him,” said Abu Hamed. “If not, I will continue to be one of his fiercest critics.”

Morsi also faces the issue of the Brotherhood itself, which has been under an official ban since 1954 – when President Gamal Abdel Nasser outlawed the group following a failed attempt to assassinate him in the Mediterranean city of Alexandria – and existed as an underground movement during the Mubarak years. Egypt’s administrative court is scheduled in September to review lawsuits calling for a complete dissolution of the Brotherhood movement and the Freedom and Justice Party, which Morsi headed until he was declared president on Sunday.

Abu Hamed said he would closely watch how Morsi treats the Brotherhood. “As president, will he accept a secret, underground movement that is not under any form of official monitoring?” he asked.

Morsi, 60, won 13.2 million votes to Shafik’s 12.3 million, margin of just 4 percentage points in a runoff election in which just half of Egypt’s 50 million registered voters cast ballots. For those pessimistic about Egypt’s future under an Islamist president, his speech Sunday night calling for national unity and reconciliation had little effect.

“Those who elected a president with a religious background abandoned the demands of the revolution,” said Fikry.