"It's not easy, but it's the first sacrifice that can be offered to the Lord," says the 50-year-old elementary school principal. "From the first moment of the day to the last, all belong to God."
Aguilar is one of 85,000 worldwide followers of the Roman Catholic movement Opus Dei--"God's work" in Latin.
Disciples believe that professional dedication and personal sacrifice--some even wear hair-shirts and flagellate themselves--are pathways to holiness.
On Oct. 6, Opus Dei founder Josemaria Escriva de Balaguer, who died in 1975, will be canonized at the Vatican after one of the shortest waiting times in church history.
The ceremony is expected to draw crowds reminiscent of the 1992 beatification of the Spanish priest, when hundreds of thousands of faithful and supporters thronged St. Peter's Square.
The event will be a pinnacle for a secular movement that was at first regarded warily by ecclesiastical authorities. In the country that is home to about a third of its members, the mention of Opus Dei still stirs passionate debate.
Detractors accuse it of cult-like practices such as brainwashing adherents into thoughtless devotion and blackmailing former members to keep them from revealing organization secrets. Some Spaniards suspect it of illegally acquiring wealth and conspiring to influence both church and state.
``They are a danger to society,'' said Javier Sainz Moreno, a finance and tax law professor at Madrid's Autonomous University. He claims the organization has enriched itself in a string of murky financial deals.
Escriva was born Jan. 9, 1902 in the Aragonese town of Barbastro. Three years after his ordination in 1928, he had a vision in which he said God revealed Opus Dei's mission.
God wants ordinary Christians, he wrote later, ``to be saints and apostles in the very midst of our professional work; that is, sanctifying our job in life, sanctifying ourselves in it and, through it, helping others to sanctify themselves as well.''
Despite early concerns that Escriva's message might challenge ecclesiastical authority, the church classified the movement a ``personal prelature'' in 1982. That places it outside the supervision of any diocese.
Today, some of its biggest fans are found in Rome.
The pope, who shares the founder's vehement anti-communism, is said to be impressed with Opus Dei's ability to inspire religious fervor and bring the faith into the everyday lives of Catholics.
The core of the movement is made up of ``numeraries,'' about a third of the total membership. They are celibate and live in sexually segregated homes.
Some, like psychiatrist Rafi Santos, who lives with nine other professional women, donate their salaries to the cause. She works at an Opus-sponsored social aid organization and a private clinic, and rises at the crack of dawn.
``My life is not all that different from that of any other professional. Maybe what's different is my motivation,'' said Santos, who wore a chunky diamond ring on her left hand.
Aguilar, the school principal, lives with his family of eight children. He prays and attends mass daily. He joined the movement at age 18 after visiting an Opus-sponsored youth center. ``I was impressed by the cleanliness and the discipline,'' he said.
Opus Dei's reputation for elitism started during the 1939-75 dictatorship of Gen. Francisco Franco. Many of the technocrats in Franco's later governments belonged to the movement, and are widely credited with helping cause Spain's economic boom of the 1960s.
Today, Opus Dei runs IESE, one of the nation's leading business schools; and the University of Navarra, which Escriva founded in 1952. Two of Prime Minister Jose Maria Aznar's children went to Opus-run schools.
The movement's chief prelate in Spain, Mons. Tomas Gutierrez, said in a written response to questions from The Associated Press that members are forbidden by Opus Dei's laws from hiding anything.
Those in public office ``are exclusively subject to the norms and guidelines'' of their government, he said, notwithstanding Opus Dei's strict adherence to Vatican doctrine on issues such as abortion and birth control, which are legal in Spain.
Gutierrez rejected the conspiracy allegations, maintaining the organization's financial assets are ``scarce'' - no more than needed to cover education and salaries of its 1,800 priests and sponsored activities. He didn't give any figures.