Forgiveness is very important in Islam

Allah is Ar-Rahman, the Most Compassionate, and Ar-Raheem, the Most Merciful. He loves that we ask Him for forgiveness and He has promised to forgive.
Say, “O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.” And return [in repentance] to your Lord and submit to Him before the punishment comes upon you; then you will not be helped.
Surat Az-Zumar 39:53-54
And seek forgiveness of Allah. Indeed, Allah is ever Forgiving and Merciful.
Surat An-Nisa 4:106
And whoever does a wrong or wrongs himself but then seeks forgiveness of Allah will find Allah Forgiving and Merciful.
Surat An-Nisa 4:110