Religious sister (Catholic) in the context of Théodore Guérin

Juxtaposition is an act or instance of placing two opposing elements close together or side by side. This is often done in order to compare/contrast the two, to show similarities or differences, etc.

A nun is a woman who vows to dedicate her life to religious service and contemplation, typically living under vows of poverty, chastity, and obedience in the enclosure of a monastery or convent. The term is often used interchangeably with religious sisters who do take simple vows but live an active vocation of prayer and charitable work in the wider society.

In Christianity, nuns are found in the Catholic, Oriental Orthodox, Eastern Orthodox, Lutheran, and Anglican and some Presbyterian traditions, as well as other Christian denominations. In the Buddhist tradition, female monastics are known as Bhikkhuni, and take several additional vows compared to male monastics (bhikkhus). Nuns are most common in Mahayana Buddhism, but have more recently become more prevalent in other traditions.

The Order of Preachers (Latin: Ordo Prædicatorum, abbreviated OP), commonly known as the Dominican Order, is a Catholic mendicant order of pontifical right that was founded in France by the Castilian priest Dominic de Guzmán. It was approved by Pope Honorius III via the papal bull Religiosam vitam on 22 December 1216. Members of the order, who are referred to as Dominicans, generally display the letters OP after their names, standing for Ordinis Praedicatorum, meaning 'of the Order of Preachers'. Membership in the order includes friars, nuns, active sisters, and lay or secular Dominicans (formerly known as tertiaries). More recently, there have been a growing number of associates of the religious sisters who are unrelated to the tertiaries.

Founded to preach the gospel and to oppose heresy, the teaching activity of the order and its scholastic organisation placed it at the forefront of the intellectual life of the Middle Ages. The order is famed for its intellectual tradition and for having produced many leading theologians and philosophers. In 2018, there were 5,747 Dominican friars, including 4,299 priests. The order is headed by the master of the order who, as of 2022, is Gerard Timoner III. The Blessed Virgin Mary, Mary Magdalene, Augustine of Hippo and Francis of Assisi are the Principal Patrons of the order.

The Most Sacred Heart of Jesus (Latin: Cor Jesu Sacratissimum) is one of the most widely practised and well-known Catholic devotions, wherein the heart of Jesus Christ is viewed as a symbol of "God's boundless and passionate love for mankind". This devotion to Christ is predominantly used in the Catholic Church, followed by high church Anglicans, and some Western Rite Orthodox. In the Latin Church, the liturgical Solemnity of the Most Sacred Heart of Jesus is celebrated on the third Friday after Pentecost. The 12 promises of the Most Sacred Heart of Jesus are also popular.

The devotion is especially concerned with what the church deems to be the long-suffering love and compassion of the heart of Christ towards humanity. The popularization of this devotion in its modern form is derived from a Roman Catholic nun from France, Margaret Mary Alacoque, who said she learned the devotion from Jesus during a series of apparitions to her between 1673 and 1675, and later, in the 19th century, from the mystical revelations of another Catholic nun in Portugal, Mary of the Divine Heart, a religious sister of the congregation of the Good Shepherd, who requested in the name of Christ that Pope Leo XIII consecrate the entire world to the Sacred Heart of Jesus. Predecessors to the modern devotion arose unmistakably in the Middle Ages in various facets of Catholic mysticism, particularly with Gertrude the Great.

Ignacia del Espíritu Santo luco, also known as "Mother Ignacia" (February 1, 1663 – September 10, 1748) was a Filipino religious sister of the Catholic Church. She was known for her acts of piety and religious poverty and founded the Congregation of the Sisters of the Religious of the Virgin Mary, the first native Filipino female congregation with approved pontifical status in what is now the Republic of the Philippines.

Mother Ignacia del Espíritu Santo was declared venerable by Pope Benedict XVI on July 6, 2007.