The painting of St. Paul was probably created with the whole altar from the foundation of father Andrzej Strzałkowski in the years 1700-1703. St. Paul was presented holding a book in his hand which is a symbol of his participation in an Apostolic Mission. This attribute was present in the saint's iconography in the early-Christian art already. In his other hand, he is holding a sword to reference his martyr's death. Unfortunately, the author of the work remains unknown.
Maia Działo, "St. Paul ", [in:] "The Sacred Lesser Poland Heritage", 2021, source: https://sdm.upjp2.edu.pl/en/works/st-paul-12