All things, even sin

“Job says that “the life of man upon earth is a warfare and his days are like the days of a hireling.” But upon His servants the Lord bestows His grace; although as Saint Paul says, “to them that love God all things work together unto good,” to the very end. All things — graces, natural qualities, contradictions, sickness, and, as Saint Augustine says, even sin. For God permits sin in the lives of His servants, as He permitted Peter’s denial, that He may lead them to a deeper humility and thereby to a purer love.”
Père Réginald Garrigou-Lagrange, O.P.