First faulty extreme: Allah is merciful, so there is no need to fear accountability for sin.
Second faulty extreme: Once a sin is serious, hope in Allah's mercy is pointless.
Correct formulation: Fear and hope both have a place in the believer's life. Trust in mercy does not authorize sin, while recognition of warning does not close the door to repentance and mercy.
Application: Remorse, repentance, reform and renewed obedience combine fear with hope. Both complacent security and total despair contradict moderation.