I understand that when a person puts their will above God’s, they are sinning. However, that only completes half of the picture. The Catholic Chirch views God’s will as indomitable, but how does the Catholic Church view the will of a mere man? Is there ever occasion to consider man’s will first? And if so, why does the Church preach that God’s will comes before all else?
Man’s will is finite and God’s will is infinite. It is never right to choose man’s will over God’s will. As you pointed out, this is a sin. Man is created for God and not for himself. As such, God has an absolute right to man’s obedience and submission. He is the author and sustainer of man’s very existence. Man owes everything to God.
But even when man’s will diverts from God’s will, God orders it to a greater good in accordance with his Divine wisdom.