We can never obey any one as we ought unless we trust him, and we cannot trust him unless we place reliance on his word. This reliance on what God says to us is thus the beginning of obedience to His commands; it is the acceptance of what He tells us to receive as true, not because we ourselves see it to be true, but because He vouches for its truth. Our intellect must first submit before our will consents to follow. Thus faith is the keystone of obedience, and our obedience will be in proportion to our faith.
The heroes of faith commemorated by Saint Paul in the Epistle to the Hebrews (of which we shall speak hereafter), were all of them primarily remarkable for their Obedience. They did great things for God and things that would have been impossible without a strong and vivid faith. God asked of their obedience many things repugnant to human nature. But the obedience of the saints was made easy by their faith. They saw Him Who is invisible; they heard His words, and knowing them to be the words of God, obeyed with joy. Have I this strong faith that makes obedience easy?
All sin is accompanied by a weakness of faith. If we believed and realized with the certainty of an undoubted faith what sin is before God, what God is, and what is the consequence of disobeying Him, disobedience would be impossible. It is because our faith is already clouded by sin that we venture to set at nought the sway of the Omnipotent God. I Pray that you may so have God before your eyes as to make it impossible for you to sin.
- text from Beautiful Pearls of Catholic Truth; it has the Imprimatur of Archbishop Michael Augustine Corrigan, Diocese of New York, 6 October 1897