Where there is devotion and faith any image will be sufficient, but if they are lacking none will suffice. Our Lord was indeed a living image during his sojourn in this world; nevertheless, those who were faithless received no spiritual gain, even though they frequently went about with him and beheld his wondrous works. This is why he did not perform many mighty works in his own country, as the Evangelists declare (Mt. 13:58; Mk. 6:5-6).
Saint John of the Cross
The Ascent of Mount Carmel, III, Chap. 36, no. 3
John of the Cross, St. 1991, The Collected Works of St. John of the Cross, Revised Edition, translated from the Spanish by Kavanaugh, K and Rodriguez, O with revisions and introductions by Kavanaugh, K, ICS Publications, Washington DC.