How the sinner is deceived

"The devil leads sinners to hell, not with their eyes open, but with them closed: first he blinds them, and then he leads them to suffer entirely in his company. (...) "Do this sin and then you will confess". This is the deception with which the devil has led thousands of Christians to hell. For it is difficult to find a Christian who intends to condemn himself. All those who sin, sin in the hope of confessing; and that is why so many have been condemned afterwards. 

"But God is merciful." Here you have another deception by which the devil encourages men to sin and to persevere in it. One author says that more souls are led to Hell by false hope in the mercy of God than by divine justice. 

And so it happens, indeed, because many blindly trusting in the mercy of God, continue in the path of sin, and are miserably condemned. "God, they say, is merciful." He is indeed: no one denies it. Yet how many does he send to Hell every day? He is merciful to sinners, but only to those who repent of having offended Him, and fear to offend Him again. But with those who abuse His mercy to offend Him more, He is just." 

(St. Alphonsus Maria de Liguori, "Abeviant Sermons for all the Dominican Sisters of the Year").