As we should neither be too afraid of Allah that we lose hope in Allah nor we should be in too much love with Allah that we forget the boundaries (means that we start crossing the boundaries set by Allah by thinking Allah will forgive). Then, how to keep balance between love of Allah and fear of Allah ?
Imam Sadiq has quoted from Luqman's will to his son:
You must fear Allah similar to: one who has done the same amount of good done by all humans and jinn, still fears Allah will requite him.
and You must have hope in Allah similar to: one who carries the sins of all humans and jinn, but hopes Allah will forgive him . Usul al-Kafi. Vol.2 Pg.67
Such a mindset will always keep you balanced. You won't ever let yourself too loose to sin, neither you would ever lose hope in him forgiving your sins.
(I improved my translation)
Additional explanation about what the fear means:
- Never be in a state of pride, I'm good, I'm great. Insead fear God, see him present at every moment regardless of your past.
- The narration is just a statement. It just means even if you have a huge amount of good done...enough that it equals the good of all the humans and jinn—still look at your sins and find yourself deserving of his wrath/justice.