The idea of gods and goddesses inspiring writings and the arts comes from Greek mythology but then Paul had a classical education so he would have known that.
The Muses, the personification of knowledge and the arts, especially literature, dance and music, are the nine daughters of Zeus and Mnemosyne(memory personified). Hesiod's account and description of the Muses was the one generally followed by the writers of antiquity. It was not until Roman times that the following functions were assigned to them, and even then there was some variation in both their names and their attributes: Calliope (epic poetry), Clio (history), Euterpe (flutes and lyric poetry), Thalia (comedy and pastoral poetry), Melpomene (tragedy), Terpsichore(dance), Erato (love poetry), Polyhymnia (sacred poetry), and Urania (astronomy).
Three ancient Muses were also reported in Plutarch's Quaestiones Convivales  (9.I4.2–4).  The Roman scholar Varro relates that there are only three Muses: one who is born from the movement of water, another who makes sound by striking the air, and a third who is embodied only in the human voice. They were Melete or Practice, Mneme or Memory and Aoide or Song.
Gustave Moreau, Hesiod and the Muse (1891)— Musée d'Orsay , Paris
However the Classical understanding of the muses tripled their triad, set at nine goddesses, who embody the arts and inspire creation with their graces through remembered and improvised song and stage, writing, traditional music, and dance.
In one myth, King Pierus, king of Macedon, had nine daughters he named after the nine Muses,  believing that their skills were a great match to the Muses. He thus challenged the Muses to a match, resulting in his daughters, the Pierides, being turned into chattering magpies  for their presumption.