Human reason has been Dante’s primary guide through Hell (in Inferno) and Purgatory (in Purgatorio). However, reason is not sufficient to get him to Heaven; he must have trust and faith in Christ as the Savior and in God. One of the most prevalent examples of faith is prayer – a selfless plea to God that He let only blessings fall on the object of the prayer. But for Dante, faith must be solidified even further. Hence the appearance of his new Christian guide, Statius, as a replacement for the pagan Virgil.
From Statius’ explanation of the birth of the human soul, one could argue that acquiring faith over human reason is the most important message in Purgatorio.
Because Statius has been converted to Christianity by Virgil’s poetry, Virgil should not be condemned to Hell.