IX. Moving to the third vault, in the left web we find the ninth Article of the Creed: SANCTAM ECCLESIAM CATHOLICAM, SANCTORUM COMMUNIONEM (“the holy Catholic Church, the communion of saints”) presented by the apostle Matthew. Across from him, Zephaniah displays his scroll with the words HEC EST CIVITAS GLORIOSA QUE DICITUR EXTRA ME NON EST ALTERA (“This is the rejoicing city that said ‘I am it and there is none besides me’”). This scene has a rather complex iconography: in the center is the figure of a Pope, symbolizing the Church, resting on Peter who is semi-reclining on the ground. With his left hand the pope gives Peter the keys, while with his right he administers Baptism to a catechumen immersed in the water of a baptismal font. Saint Peter’s position refers to the Gospel of Matthew 16:18, “You are Peter, and on this rock I will build my church.”
X. The tenth web, proceeding counterclockwise, presents the article CREDO REMISSIONEM PECCATORUM (“I believe in the remission of sins”) in the scroll held by the apostle Simon. Corresponding to him on the other side, Malachi repeats words from his book: ‘CUM HODIO [sic] ABUERIS [sic] DIMITTE’ (“If you hate it, send it away”). In the scene a priest lays his right hand on the head of the praying penitent kneeling in front of him; the moment illustrated is that of absolution from sin “in the name of the Father, and of the Son, and of the Holy Spirit.”
XI. In the web next to the right wall of the Baptistery is shown the article CREDO CARNIS RESURRECTIONEM (“I believe in the resurrection of the flesh”). This truth of faith is pronounced by Judas Thaddeus, across from the prophet Zechariah, whose scroll contains a passage from his book SUSCITABO FILIOS TUOS (“I will arouse your sons”). In the upper part of the scene, four angels blow the trumpets to gather together the “chosen ones from the four winds, from one end to the other of the heavens.” At the mighty sound, the dead emerge from the deep crevices in the ground and assume various poses. The scene fills with bodies, rendered with a strong sense of three-dimensionality.
XII. The apostles’ Creed ends with the article CREDO VITAM AETERNAM (“I believe in eternal life”) presented by Matthias, the apostle who was added to the Twelve to replace Judas Iscariot. The prophet Obadiah shows the prophesy from his book ET ERIT DOMINO REGNUM (“and the kingdom shall be the Lord’s”). The cycle thus concludes with the serene vision of Paradise, a garden covered with flowers. The composition of the scene is divided into two parts: above are shown Christ and the Virgin Mary resting on a cloud of cherubs, while below are angel musicians and some Saints, among whom we can recognize Saint Bernardine and the four Patron Saints of Siena: Ansanus, Crescentius, Sabinus, and Victor.