St. John Vianney
“UNWORTHY Communions are made very often. How many there are who have the temerity to come to the Holy Table with sins unconfessed or disguised in Confession. How many have not the contrition that the good God demands of them, and keep a secret will to commit sin again and not to make every effort to correct themselves. How many do not avoid the occasions of sin when they could do so, and bring to the Holy Table enmities in their heart! If ever you have been in these dispositions when going to Holy Communion, you have been guilty of sacrilege.”
Source: St. John Vianney, The Meditations of the Curé D’Ars