As we mark the 20th anniversary of Pope St. John Paul II’s death and birth into eternal life on April 2, it’s key to focus on the most important lessons of his life.

His legacy is monumental, inside and outside the Catholic Church — one of the reasons why many think he should be officially named John Paul “the Great,” alongside Leo the Great (440-461), Gregory the Great (590-604) and Nicholas the Great (850-867).

He was great, even outside the Church, because of his role in international affairs — helping catalyze the collapse of Soviet communism, resisting efforts by worldly superpowers to impose international human rights abuses, and giving hope and courage to suffering peoples everywhere. He visited 129 countries, traveling more than 700,000 miles — more than all of his predecessors combined and nearly three times the distance of a round trip to the moon.

He was hugely influential inside the Church, implementing the documents of the Second Vatican Council and giving us one of the two most monumental magisterial legacies in papal history (alongside Leo XIII).

He promoted an anthropology adequate to counter the harmful philosophical “isms” of the modern and post-modern age, teaching us that the Church’s teachings on love, marriage, sex and family are part of the “good news,” not the “bad,” and equipping the Church with the tools needed later to respond to gender ideology.

He promoted hundreds of thousands of priestly vocations across the globe through his personal witness and love of his own priestly vocation, as he reformed many aspects of priestly and religious life, seminary formation and especially moral theology.

He gave clear answers to the questions of Catholic identity, vocation and mission, and in his document on the Gospel of Life made it clear that those who support abortion and euthanasia are supporting intrinsic evils never compatible with Catholic faith and love.

He stirred up a deeper, more scripturally- and doctrinally-based devotional life, especially toward the Blessed Mother, and gave us five new mysteries of the Rosary to ponder.

He founded World Youth Days and changed forever the Church’s approach to young people.

He was a pope of suffering, not only surviving a 1981 assassination attempt, infected blood transfusions, bone breaks and several years on public display with Parkinson’s disease, but becoming one of the modern world’s most well-known images of Christian perseverance in a euthanizing age.

His greatest legacy, however, is about sanctity, a message he personified and proclaimed.

Saints are gifts of God to the people of each age. They show us how to live. They teach us how to love. They help us learn to die. They reveal to us our exalted origin, dignity and destiny. They make the life of faith attractive and Christian hope realistic.

John Paul II was the pope of the universal call to sanctity — a fundamental teaching of the Second Vatican Council, which affirmed that “all in the Church … are called to holiness.” He re-proposed to all, through words and witness, the high standard of ordinary Christian living.

During his 26 years and 7 months as successor of St. Peter, he canonized from all walks of life 482 saints and beatified 1,344, more than all his predecessors from the previous five centuries combined. He raised to the altars not merely martyrs, founders of religious orders, bishops, priests, nuns and other religious, but married couples, people from various professions and even young children.

He did not just celebrate them but sought to imitate them. He told his authoritative biographer, George Weigel, that people erred when they tried to understand him only “from the outside,” from all that he did publicly on the biggest stages. “But I can only be understood from inside,” he confessed.

To get to know him from the inside meant to understand him as a devoted disciple and ardent apostle of Jesus Christ — someone who as a layman, priest, bishop and pope sought to relate to God with heroic faith, hope and love. As his successor would preach at his funeral Mass two decades ago, “Follow me … can be taken as the key to understanding the message that comes to us from the life of our late beloved Pope John Paul II.”

To follow Jesus faithfully — to be holy as he is holy, to love as he loves — is a summary of his life and of the Christian life.

John Paul II wrote in his ecclesial game plan for the third Christian millennium, Novo Millennio Ineunte (2001), that the Church is essentially a vocational school meant to train people to become saints, just as much as vocational-technical high schools train students to become carpenters, electricians, cooks and plumbers.

“I have no hesitation,” he stressed, “in saying that all pastoral initiatives must be set in relation to holiness.” By this, he did not mean just that preaching, celebrating the sacraments, prayer and works of mercy must be connected to the work of sanctification, but also that Catholic education, health care, social justice work, charities, rectory and chancery work, and the setting of budgets need to be related to holiness as well. Everything the Church does must be geared to divinizing the human person.

“It is necessary,” he emphasized, “to rediscover the full practical significance of … the universal call to holiness.” The call to become a saint must be made practical, as “a task that must shape the whole of Christian life.” John Paul II sought to illustrate the practical aspects of holiness in his beatifications and canonizations of so many “who attained holiness in the most ordinary circumstances of life.”

But he also recognized that just as singers, athletes, artisans and professionals need both teaching and training, so the Church has to make sure that all the faithful recognize that they’re called to true spiritual greatness in their day-to-day life and to provide them an adequate instruction to help them achieve that grandeur.

He challenged those Christians who believed that the Christian life is compatible with “a life of mediocrity, marked by a minimalist ethic and a shallow religiosity,” saying that baptism is an introduction into the holiness of God and sets a Christian on a trajectory to be “perfect as your heavenly Father is perfect.”

He also challenged those who misunderstood the ideal of Christian perfection as “some kind of extraordinary existence, possible only for a few ‘uncommon heroes’ of holiness.”

We don’t need to wear a hairshirt, fast on bread and water for years, learn ancient Hebrew, flee to a desert monastery, or spend eight hours a day in Eucharistic adoration. Rather, he said, the “ways of holiness are many, according to the vocation of each individual.” But he insisted, “The time has come to re-propose wholeheartedly to everyone this high standard of ordinary Christian living,” stating that “the whole life of the Christian community and of Christian families must lead in this direction.”

To help people meet this standard, he said, the Church must provide “genuine training in holiness, adapted to people’s needs.” Among the many treasures of spiritual help offered by the Church — the sacraments, the word of God, retreats, approved movements, magisterial documents and so much more — he highlighted six in particular, encouraging all Catholics to open themselves to receive all they contain: grace, prayer, the Mass, the Sacrament of Reconciliation, listening to the word of God, and proclaiming the word of God in word and deed. These means of holiness are offered to everyone in the Church, from someone just baptized at the Easter Vigil to the Pope himself. Pope John Paul II’s life shows us what happens when one avails oneself of those treasures.

The Church, while always remaining a hospital for sinners, exists to be a school of saints, meeting us wherever we are and training us to respond all the way to Christ’s call “Follow me!” in the day-to-day circumstances of our lives. It’s a worldwide exercise room to help us work out the moral muscles of the virtues so that we may be capable of real heroism in faith, hope and love.

As we celebrate the 20th anniversary of his natus spiritalis, let us heed John Paul II’s oft-repeated words, “Be not afraid!” and with courage respond to his witness and intercession to make fully practical this call to holiness he spent his pontificate echoing and enfleshing throughout the world.