Modernism’s guiding idea was to make a clean break from the past. From the sleek whitewashed buildings of Le Corbusier to the understated, angular paintings of Piet Mondrian, its architects and artists were committed to severing ties with old ideas and stagnant institutions. As the Bauhaus School founder Walter Gropius put it, the idea was to create a ‘new structure for the future’ that would be more equal and rational. This campaign of total social reinvention emerged after the carnage of the First World War, and reshaped everything from city streets to domestic interiors, libraries and museums. Modernism pitted itself against aspects of public life that celebrated ostentation and hierarchy. Religion in particular seemed like the antithesis of modernity. Its archaic rules and baroque iconography encapsulated the irrationality of the world that modernists were leaving behind.

For modernists, religion was a particularly awkward topic. Some rejected the role of the church and other religious institutions. Others advocated for a new kind of spirituality that was more personal and cerebral, and less rooted in ancient institutions. Some even worked on commissions to build new churches or created ecclesiastical artworks in the hope of transforming the way that people communed with God through bold new design. Beneath these differences of opinion, however, 20th-century modernists were united by the idea that the public realm and its civic buildings should be secular spaces devoid of religious imagery.

This kind of secular modernism was, however, only one variety among many. Though we tend to associate the movement with huge brutalist skyscrapers such as Ernő Goldfinger’s Trellick Tower in London or monumental government buildings such as United Nations Secretariat Building in New York, modernism had a startlingly different – and often more surprising – flavour beyond the West. Exhibitions such as the Victoria and Albert Museum’s Tropical Modernism: Architecture and Independence and Brasil! Brasil! The Birth of Modernism have introduced audiences to radically different versions of the movement, from the designs of the Ghanaian architect John Owusu Addo for independent Accra, to the colourful avant-garde paintings of Brazilian artist Tarsila do Amaral.

There’s no clearer illustration of this radical synthesis than Nigeria, where a spectacularly different kind of modernism took shape in the 1960s, as people set about creating art and buildings that were strikingly original. Although the country had gained independence from Britain in 1960, traces of the colonial administration remained. Some of the British art teachers and architects who had been dispatched to Nigeria from the imperial metropole stayed on after colonial rule, and the ideas they had brought with them remained influential. Nigerian artists and architects took these ideas and reinvented them. Rather than erasing all traces or religion from their new art they actively embraced it, weaving images, symbols and themes from the dominant faiths of Christianity, Islam and traditional spiritualism into the art they began to create.

As Nigerian Modernism, a new exhibition at Tate Modern, explores, this aesthetic movement echoed international modernism while being completely unique. Independence gave a new cultural licence to art schools, and artists used this freedom to form cultural movements such as the Mbari Club at the University of Ibadan near Lagos, founded in 1961 by Wole Soyinka and other poets, playwrights, sculptors and painters. There, artists including the painter Uche Okeke developed new styles of image-making that mixed the international with the indigenous. They trialled their paintings on the walls of the clubhouse, publishing images of them in the pages of the society’s popular Black Orpheus magazine.

At the Nigeria College of Arts, Science and Technology in the north of the country, the Zaria Art Society was founded in the late 1950s. Here, a rebellious group of artists created a new kind of art known as ‘natural synthesis’, which rejected the strictures imposed by the colonial art curriculum and used new techniques to represent traditional indigenous subjects. Members of the group, including the painter and sculptor Bruce Onobrakpeya, drew on European art styles such as Vorticism to depict indigenous life. Onobrakpeya also used imported linocutting and etching tools to invent brand new printing techniques, producing images of life in his native Delta State.

Today, you can still see traces of this movement in Nigeria’s major cities. At the National Theatre in Lagos, the sleek concrete and steel structure that was once the crown jewel of a modernist cityscape is home to a vast panoramic mural by Agbo Folarin, a sculptor and art teacher from southwest Nigeria. It hangs in the main foyer and shows a futuristic, abstracted Yoruba kingship ceremony attended by traditional deities, which is cast in gleaming copper. Nearby, huge, fragmented stained glass windows created by the northern-Nigerian artist Yusuf Grillo bring a sacred aura to this civic space. A wooden frieze by the sculptor Erhabor Emokpae wraps around the entire building and incorporates symbols from Nigeria’s major faiths into a wild, angular composition. In the adjoining National Gallery, artworks by Bruce Onobrakpeya translate biblical and folkloric scenes into a futuristic series of brass-beaten panels. Here, modernism looks more like a kaleidoscope than a monolith – with copper, bronze and wood put to use alongside concrete, steel and glass to fashion new images of historic traditions. By absorbing the old into the new and the divine into the civic, these artists dismissed the idea that religion ought to be separate from politics.

Nigeria has long been a nation where politics and faith are tightly intertwined. In the period since independence, formidable Christian pastors and powerful Islamic imams have come to exercise an ever-greater sway over the country’s federal politics. Today, Nigeria’s presidents, vice-presidents and regional governors rely on the backing of religious leaders and their congregations to win elections and maintain their authority. Nigeria’s distinct brand of modernism reflected this proximity between faith and civic life, and its leading artists and architects sought to narrow the gap between them. Today, at the National Theatre, auditoriums designed as civic venues regularly plays host to huge Pentecostal Christian congregations.

Western modernism wanted to eliminate religion from civic life. Architects abolished it from their designs, and artists avoided it. Yet religion has remained a pervasive feature of contemporary politics around the world. As religion comes to play an increasingly central role in western politics, Nigeria’s version of modernism, which sought to absorb religion rather than mask it, should give us pause to consider whether the cold rationalism of Le Corbusier and Walter Gropius was merely the performance of a break from the past that the West had never really left behind.