Sometimes–almost habitually, indeed, or at least very frequently–I would find relief after communicating. There were times, in fact, when the very act of approaching the Sacrament would at once make me feel so well, both in soul and in body, that I was astounded. I would feel as if all the darkness in my soul had suddenly been dispersed and the sun had come out and shown me the stupidity of the things I had been saying and doing. At other times, if the Lord spoke only one word to me (if, for example, as on the occasion I have already described, He said no more than "Be not troubled: have no fear"), that one word completely cured me, or, if I were to see some vision, it was as if there had been nothing wrong with me. I rejoiced in God and made my complaint to Him, asking Him how He could allow me to suffer such tortures, but telling Him that I was well rewarded for them, since, when they were over, I almost invariably received favors in great abundance. My soul seemed to emerge from the crucible like gold, both brighter and purer, to find the Lord within it. So trials like these, unbearable as they may seem, eventually become light, and the soul becomes anxious to suffer again if by so doing it can render the Lord greater service. And, however numerous may be our troubles and persecutions, if we endure them without offending the Lord, but rejoice to suffer for His sake, they all work together for our greater gain--though I do not myself bear them as they should be borne, but in a way which is most imperfect.

The Autobiography of St. Teresa of Avila
St. Teresa of Avila