Of a hundred thousand delicious fruits, Eve chose that which had been forbidden to her; and doubtless if it had been allowed, she would not have eaten of it. The fact is, in a word, that we want to serve God, but after our will, and not after His.
Saul was commanded to spoil and ruin all he found in Amalek. He destroyed all, except what was precious; this he reserved, and offered in sacrifice. But God declared that He would have no sacrifice against obedience. God commands me to help souls, yet I want to rest in contemplation. The contemplative life is good, but not in opposition to obedience. We are not to choose at our own will. We must wish what God wishes; and if God wishes me to serve Him in one thing, I ought not to wish to serve Him in another. God wishes Saul to serve Him as king and as captain, and Saul wishes to serve Him as priest. There is no doubt that the latter is more excellent than the former; yet God does not care about that. He wants to be obeyed.
St. Francis de Sales , letter 233 to Madame Brulart, October 13, 1604, as published under the title of "Do the will of God joyfully," in Thy Will Be Done: Letters to Persons in the World, published by Sophia Institute Press, c. 1995 (from the English translation of the Very Reverend Henry Benedict Mackey; with editorial revisions and improvements in the translation for the 1995 edition)