[Petrosius]

The Catechism of the Catholic Church admits that private confession first came on the scene in the seventh century.

That is private confession, not confession itself. As the very quote you give states, in the early centuries it was done publicly and only for very grave sins. The sacrament existed all along, only how it was practiced changed. So what?

[Elsie]

...in the early centuries it was done publicly and only for very grave sins.

We practice what the church has ALWAYS practiced!!

[boatbums]

That is private confession, not confession itself. As the very quote you give states, in the early centuries it was done publicly and only for very grave sins. The sacrament existed all along, only how it was practiced changed. So what?

You probably mean the practice of what is called "auricular" (to the ear) confession, because NO ONE would deny that Scripture clearly teaches confession itself. Just the "private" confession as it is practiced today by going privately to a priest is what changed, contrary to the dogmatic - but false - assertion of Trent:

“If anyone denies that the sacramental confession was instituted, and is necessary for salvation, by divine Law; or says that the manner of confessing secretly to a priest alone, which the Catholic Church has always observed from the beginning and still observes, is at variance with the institution and command of Christ and is a human invention, anathema sit” (Council of Trent, Session 14, Canon 6).

Can I presume that you do not agree with what Catholicism has claimed WRT private confession being "always observed from the beginning"?