Responding to the original question,
We (all of us, that is) are forgiven by God via repentance (turning from our old ways):
“Then if my people who are called by my name will humble themselves and pray and seek my face and turn from their wicked ways, I will hear from heaven and will forgive their sins and restore their land.” --2 Chron. 7:14
And via confession:
“If we confess our sins to him, he is faithful and just to forgive us our sins and to cleanse us from all wickedness.” --1 John 1:9
Most Protestants (I am not Protestant, by the way) maintain since Christ took all sins upon himself at the Crucifixion, in the eyes of God in his position outside of the realm of time, all the sins of those who are a part of the Body of Christ are already forgiven. Yet within the realm of time (where we exist), there is a need daily to confess our sins for forgiveness, yet forgiveness does not occur based
soley on confession, as it would be impossible to confess ALL sins, but because of the believer’s repentance and God’s unending mercy. Amen?

Amen.
The Apostles receiving the ability to forgive sins was a demonstration of God’s power in them, giving validity to their testimonies. Don’t forget the numerous other signs accompanying them, as well, all given so that an unbelieving world might be convinced.