What is the Church's teaching on the Necessity of Baptism?
No need whatsoever to post a mile long dissertation.....
SESSION THE SEVENTH
DECREE ON THE SACRAMENTS
CANON II.-If any one saith, that true and natural water is not of necessity for baptism, and, on that account, wrests, to some sort of metaphor, those words of our Lord Jesus Christ; Unless a man be born again of water and the Holy Ghost; let him be anathema.
CANON V.-If any one saith, that baptism is optional, that is, not necessary unto salvation; let him be anathema.
This ^^ is the Church's teaching on the Necessity of Baptism.
Could it be more simple?