ST. JOHN OF THE CROSS:
...Since unpurified souls must undergo the sufferings of fire in the next life to attain union with God in glory, so in this life they must undergo the fires of these sufferings to reach the union of perfection; This fire acts on some more vigorously than on others, and on some for a longer time than on others, according to the degree of union to which God wishes to raise them, and according to what they must be purged of...
And here it ought to be pointed out why so few reach this high state of perfect union with God. It should be known that the reason is not that God wishes only a few of these spirits to be so elevated; he would rather want all to be perfect, but he finds few vessels that will endure so lofty and sublime a work. Since he tries them in little things, and finds them so weak that they immediately flee from work, unwilling to be subject to the least discomfort and mortification, it follows that not finding them strong and faithful in that little '(Mt. 25:21,23), ...he realizes that they will be much less strong in these greater trials.
St. John of the Cross, the Living Flame of Love. Stanza 2, No. 25-27
HAPPY FEAST OF ALL SAINTS!
Peace be with you!