The natural instinct of fallen human beings who are troubled by their consciences is to hide their sin. They do this without much thought, without stopping to consider how effective it is, without asking who they are trying to hide from and whether they can succeed.
Those who claim to have repented but who show no change of life are deceiving themselves. We must continue to require evidence of repentance as John the son of Zacharias did (Luke 3:8). When we see a new breed of Christians who claim to be able to keep many aspects of their old lives and still claim to be following Christ, we know that the enemy of souls is at work to produce false converts.