When a person chooses a sinful lifestyle, they immediately take on the daily pressure of living outside of the will of God. This robs them of their peace and contentment, for an unsettled conscience serves as an agitator. If they aren't agitated, they may have a bigger problem (salvation?).
The more trained up in the Word you become, the more stable your life becomes. This is due to the objective nature of Truth in the soul. We move from subjective living to objective living. Subjective people despise this and in many ways are jealous.