The constant faith of the Church affirms the belief in purgatory.
From the earliest of times, the Fathers of the Church taught
the existence of purgatory:
Tertullian (Rome, 160-220?),  Origen (Alexandria, 185-254?),
Cyprian (Carthage, 200-258), Ambrose (Tier, 340-397),
Augustine (Numidia, 354-430), Basil (Caesarea, 329-379),
Gregory of Nazianzus (in Cappadocia, 329-389),
John Chrysostom (Antioch, 349-407),
Gregory the Great (Rome, 540-604), and many others.