The mercy of Allah Subhanahu wa Ta’ala does not imply the absence of fearing Him. The believer who fears Allah, all the while being conscious of His mercy, is, in fact, the one who hopes for His mercy.
Allah Says:

“إِنَّمَا تُنذِرُ مَنِ ٱتَّبَعَ ٱلذِّكۡرَ وَخَشِیَ ٱلرَّحۡمَـٰنَ بِٱلۡغَیۡبِۖ فَبَشِّرۡهُ بِمَغۡفِرَةࣲ وَأَجۡرࣲ كَرِیمٍ” (Yaseen:11)
“Indeed, you can only warn those who follow the Reminder and fear the Most Merciful unseen. So give them good tidings of forgiveness and a noble reward.”