Augustine of Hippo — as excerpted in the Catena Aurea on John 20:19-25

“(Tr. cxxi. 3) The love of the Church, which is shed abroad in our hearts by the Holy Spirit, remits the sins of those who partake of it; but retains the sins of those who do not. Where then He has said, Receive ye the Holy Ghost, He instantly makes mention of the remission and retaining of sins.”