The sacred art of Jerzy Nowosielski, an outstanding Polish painter of the second half of the 20th century, is an example of the creative continuation of the Byzantine tradition in Poland, but also an embodiment of the debate with the painting tradition of the East and with the experience of the Church. Both in theory and in painting practice, the artist redefined the concept of the icon, attempting to expand its formula so that it not only spoke of the Kingdom, but also included the image of the earthly, imperfect reality of the pilgrim Church. In his designs of sacred interiors for churches of various Christian denominations, Nowosielski wanted to combine three theological disciplines and their respective ways of representation: Christology, sophiology and angelology. Beside a classical icon, called by the painter a “Christological- Chalcedonian” icon, Nowosielski demanded a “sophiological” icon, bringing into the space of a church an earthly, painful reality, traces of inner struggle and doubt – hence the presence of doloristic motifs in his icons. The “inspired geometry” also became a complement to the holy images; the artist noticed a huge spiritual potential in abstract painting, to which he eventually assigned the role of icon painting. The poetic concept of “subtle bodies” – abstract angels testifying to the reality of the spiritual world – drew from the early Christian theological thought, which argued about the corporeality of spiritual entities, from Byzantine angelology, the tradition of theosophy and occultism, but also from the art of the first avant-garde, especially that from Eastern Europe, which inherited the Orthodox cult of the image. Nowosielski’s bilingualism as a painter – practicing abstraction and figuration in tandem, including within the church – paralleled the liturgical practice of many religious communities using different languages to express different levels of reality: human affairs and divine affairs. The tradition of apophatic theology, proclaiming the truth about the “unrepresentability” of God, was also important in shaping Nowosielski’s ideas. For Nowosielski’s monumental art, the problem of the mutual relationship between painting and architecture proved crucial. The artist based his concept on the decisive domination of painting over architecture and the independence of monumental painting. His goal was the principle of creating a sacred interior as a holistic, comprehensive vision of space which leads the participants of liturgy “out of everyday life” and into a different, transcendent dimension, in which the painter saw the main purpose of sacred art. From his first projects from the 1950s till the end of his artistic practice Nowosielski tried to realize his own dream version of the “ideal church”. In many of his projects he introduced abstraction into the temple, covering the walls, vaults, presbyteries, sometimes even the floors with a network of triangular “subtle bodies”. Forced to compromise, he introduced sacred abstraction into murals, as accompanying geometries, or into stained glass windows. The interiors, comprehensively and meticulously planned, were supposed to create the effect of “passing through”, “rending the veil” – from behind which a new, heavenly reality dawned. In practice, it was not always possible to achieve this intention, but the artist’s aim was to create an impression of visual unity, a sense of “entering the painting”, of being immersed in the element of painting. Painting in space was supposed to unite a broken world, to combine physical and spiritual reality into an integral whole. When designing sacred interiors, Nowosielski used the sanctity of the icon, but also the pure qualities of painting which were to cause a “mystical feeling of God’s reality”. The aim of sacred art understood in such a way turned out to be initiation rather than teaching. In this shift of emphasis Nowosielski saw the only chance for the revival of sacred art, postulating even a shift of the burden of evangelization from verbal teaching to the work of charismatic art.