The present building was raised under the direction of master builder Caspar Seurling, largely at the initiative of Baron Erik Göran Adelswärd, who championed a shared church for the neighbouring parishes of Borg and Löt after their medieval churches proved too small. Both old churches were demolished as the new one took shape, and an inscription over the tower doorway still records the completion of the joint church in 1803.
Architecturally, Borgs kyrka is a textbook example of the sober, light-filled late Gustavian style: a spacious barrel-vaulted interior, large round-arched windows and restrained decoration intended to focus attention on preaching rather than ornament. This character was altered in the late nineteenth century, when the enclosed box pews were removed and the colour scheme changed, before restorations in 1939 and again in 1988 sought to return the interior closer to its original appearance, reinstating enclosed pews, repainting the altarpiece and pulpit in tones closer to the originals, widening the chancel and creating a new baptismal area.
The altarpiece, depicting the Sermon on the Mount, was painted in 1804 by Pehr Hörberg and donated by Baron Adelswärd. Its frame and the pulpit are the work of the Norrköping sculptor Carl Fredrik Beurling, built to designs by Fredrik Bergstedt. A notable survivor from the medieval church at Löt is the plain granite font, thought to date from around 1200, now used at the baptismal area on the epistle side.
The church also holds a small group of older objects rescued from its medieval predecessors, including northern German wood sculptures and altarpiece fragments from the late fifteenth century and a brass christening basin thought to be a sixteenth-century German work. In the sacristy hang two seventeenth-century oval portraits with Beurling frames; local tradition recalls that these were long hidden behind black paint on the church's number boards until rediscovered during a nineteenth-century visit and later confirmed in a 1936 restoration.
The organ was originally built in 1807 by Pehr Schiörlin of Linköping, and although its mechanism has been rebuilt more than once, the historic case survives. The gallery front is decorated with an early nineteenth-century painting by Olof Littorin depicting King David's orchestra, a lively decorative touch in an otherwise restrained interior.