Without forgiveness, then the community must turn their back on the sinner and cast them out forever.

If sin can be forgiven, if the sinner changes their ways, stops sinning and strives every day to earn forgiveness, then they may be permitted to contribute to the community, and the community can care for them in turn.

Is it enough? That isn't up to us. God will judge them soon enough.

If they will not stop sinning, then they are excommunicated and cast out. There are not unlimited chances to earn the forgiveness of the community.

Also, bear in mind that Jesus was very clear that people should obey the law. The role of the church is to care for the spiritual needs of a community, not the need for law and justice. That is left to a different, mortal authority.

This is why priests attend and counsel prisoners to be put to death. Even if they have never sinned again, that doesn't erase the past nor undo the judgement of the law. Even if they die with their soul in a state of grace, they are still put to death. What comes after that is up to God.