How Venial Sin Spoils
Venial sin is a very great evil in its effects. As dying flies spoil the sweetness of the ointment, so venial sin corrupts virtuous actions; and when it affects the foundation or principal intention of them it diminishes their value to such a degree that, ceasing to be acts of a supernatural order, they no longer merit eternal rewards.
From Principles and Practices
Compiled by Rev. J. Hogan of The Catholic Missionary Society
Published by Burns Oates & Washbourne Ltd., Publishers To The Holy See
Nihil Obstat; Eduardus J. Mahoney, S.T.D. Censor deputatus.
Imprimatur; Edm. Can. Surmont, Vicarius generalis.
First printed in 1930