"When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come."
- St. John 16:13
Those are words from the mouth of our Lord Jesus Christ Himself, that with the coming of the Spirit -- the Spirit we received at baptism, and with which we were sealed in confirmation -- we will be guided "into all the truth." To be guided into all the truth is but part of the equation. We have our part to play, which involves grasping hold of the truth, incorporating it into our lives, and allowing it to guide our thoughts, words, and deeds.
Why is it that even a child understands the law of nature, when he is told that if he walks in front of a speeding car he'll be seriously hurt or even killed, and yet otherwise-intelligent people think they can hear God's commandments and ignore them with no penalty?