Will we be free to sin in heaven? . . . If we answer no, we seem to lack something: free will. If we answer yes, we lack something else: moral perfection. The Heavenly question thus lands us squarely into an earthly and present issue concerning the nature of freedom and of morality and may help us to puncture one of modernity’s most pervasive and destructive illusions: the association of freedom with rebellion and of obedience with unfreedom.1218 Peter Kreeft, Everything You Ever Wanted to Know about Heaven We sin because we see sin as a bargain. We unconsciously calculate that it’s worth it, that it pays, that “justice is not more profitable than injustice.” Sin seems to be simply a choice between alternative life-styles on earth. But if we recognize that all sin is Hellish, if we see sin as Hell wearing an earthly mask, we will fly to the Father in fear.
~ Peter Kreeft, [Everything You Ever Wanted to Know about Heaven]