How do Calvinists Misreaed 1 John 1.9 an 1 John 2.1-2?

Forgiveness for restoring fellowship

“My little children, these things write I unto you that ye may not sin. And if any man sin, we have an Advocate with the Father, Jesus Christ the righteous: and he is the propitiation for our sins; and not for ours only, but also for the whole world” (1 John 2.1-2). “If we confess our sins, he is faithful and righteous to forgive us our sins, and to cleanse us from all unrighteousness” (1 John 1.9). . . .

. . . There is still the possibility of sinning after we are saved. As we sin, our fellowship with God is immediately cut. Such fellowship is not restored until our sins are forgiven. If we sin, we must confess our sins according to 1 John 1.9, acknowledging that we have done wrong in a certain matter and asking God to forgive us. By such confession our fellowship with Him will be restored. . . .

1 John 1.9 is not about OSAS Arminianism or Calvinism. It is about believers who are "my little children" who have sinned subsequently after being saved that is blocking fellowship with God.

The confession is needed for the restoring. "Also for the whole world" is the whole world of believers. This is not about initial salvation -- sufficient grace to have the free choice or irresistibly imposed salvation --, but restoring oneself to God for one who is already saved but transgressed after being saved.