A Voice from the Past - Leo the Great

For the adversary having been proved ineffective in open persecutions now exercises a hidden skill in doing cruel hurt, in order to overthrow by the stumbling-block of pleasure those whom he could not strike with the blow of affliction.

Leo the Great, 400-460, Sermons of Leo the Great, Sermon XXXVI, III, (translated by Rev. Charles Lett Feltoe, Nicene and Post-Nicene Fathers, Philip Schaff and Henry Wace, T & T Clark and Wm. B Eerdmans Publishing, 1997, Second Series, Vol. XII, p. 151).

Can the good times be more dangerous to our spiritual life than the bad times? How can we prevent this?