Even though Jeremiah tells us that “it is not in a man who walks to direct his own steps,” (Jer. 10:23), some still attempt to do so. The result is spiritual chaos. In Romans, chapter ten, Paul said that the Jewish nation was in a lost condition due to their rejecting God’s righteousness while following their own.
It is crazy for a human being to reject God's guidance as he strives to live a spiritual life. It is so easy to be deceived— either by others or by one’s own self— that we must listen, learn, and apply the teachings of God. The classic example of Saul of Tarsus makes this point exceptionally clear. Saul was a devout Hebrew religions leader who thought he was correct in opposing Jesus of Nazareth by persecuting the church.
Obviously, the conscience of man is not a safe guide in religion. We cannot be guided by on feelings because they are often deceptive. We feel a certain way due to evidence that we have received. If that evidence is false, our feelings will be misguided also. If sincerity alone will save us, Christ did not have to die.
Men will be lost forever if they attempt to guide themselves. It is the duty of Christians to point sinners to “the Lamb of God who takes away the sin of the world” (John 1:29).