Where signs and testimonies abound, there is less merit in believing.
God never works these marvels except when they are a necessity for believing. Lest his disciples go without merit by having sensible proof of his resurrection, he did many things to further their belief before they saw him. Mary Magdalene was first shown the empty sepulcher, and afterward the angels told her about the resurrection so she would, by hearing, believe before seeing. As St. Paul says: Faith comes through hearing [Rom. 10:17]. And though she beheld him, he seemed only an ordinary man, so by the warmth of his presence he could finish instructing her in the belief she was lacking [Mt. 28:1-6; Lk. 24:4-10; Jn. 20:11-18]. And the women were sent to tell the disciples first; then these disciples set out to see the sepulcher [Mt. 28:7-8]. And journeying incognito to Emmaus with two of his followers, he inflamed their hearts in faith before allowing them to see [Lk. 24:15-32]. Finally he reproved all his disciples for refusing to believe those who had told them of his resurrection [Mk. 16:14]. And announcing to St. Thomas that they are blessed who believe without seeing, he reprimanded him for desiring to experience the sight and touch of his wounds [Jn. 20:25, 29].
Thus God is not inclined to work miracles. When he works them he does so, as they say, out of necessity. He consequently reprimanded the Pharisees because they would not give assent without signs: If you do not see signs and wonders, you do not believe [Jn. 4:48]. Those, then, who love to rejoice in these supernatural works suffer a great loss in faith.
Saint John of the Cross
The Ascent of Mount Carmel, III, ch. 31, nos. 8–9
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.