St. John Chrysostom addresses candidates for baptism
comparing their spiritual preparation
to painting:
Let the same thing happen now which occurs in the case of painters. They set forth their wooden tablets, draw white lines around them and trace in outline the royal images before they daub on the true colors. They are perfectly free to erase the sketch and to substitute another instead, correcting mistakes and changing what turned out badly. But after they go ahead and daub on the pigments, they can no longer erase again and substitute, since they injure the beauty of the image by doing so, and it becomes a matter for reproach. You do the same thing. Consider that your soul is an image. Before daubing on the true color of the Spirit, erase the bad habits which have become implanted in you...The bath takes away the sins, but you must correct the habit, so that after the pigments have been daubed on and the royal image shines forth, you may never therafter blot it out or cause wounds or scars on the beauty which God has given you. (Catech. illum. 12.23-24, trans. P.W. Harkins, Baptismal Instructions, ACW31.)