St. John Vianney
“Before giving His adorable Body and precious Blood Jesus washed the feet of the Apostles to show us that we must be free from sin, even the slightest, and that we should have no affection for them. The purity of Jesus is so great that the least fault prevents us from being united to Him as completely as He would wish. Venial sin, it is true, does not make our Communion unworthy, but it is the reason why we profit so little from it.”
Source: St. John Vianney, The Meditations of the Curé D’Ars