III. The September fast calls us in this public way to self-amendment
To this unconquerable strength of unity, therefore, dearly-beloved, we are even now invited by the solemn Fast of the Seventh Month, that we may lift our souls to the Lord free from worldly cares and earthly concerns. And because, always needful as this endeavour is, we cannot all adhere to it perpetually, and often through human frailty we fall back from higher things to the things of earth, let us at least on these days, which are most healthfully ordained for our correction, withdraw ourselves from worldly occupations, and steal a little time for promoting our eternal welfare.
“For in many things,” as it is written, “we all stumble.” And though by the daily gift of God we be cleansed from various pollutions, yet there cling to unwary souls for the most part darker stains, which need a greater care to wash them out, a stronger effort to destroy them. And the fullest abolition of sins is obtained when the whole Church offers up one prayer and one confession. For if the Lord has promised fulfilment of all they shall ask, to the holy and devout agreement of two or three, what shall be denied to many thousands of the people who unite in one act of worship, and with one breath make their common supplications?
Source: Sermons (New Advent)