But, I see the Catholic theologians teach that it is maintained by obedience to Catholic rules and regulations, etc. On top of that, there is prayer to Mary, purgatory, etc. I find these to be unbiblical. Arise, and be baptized, and wash away thy sins, calling on the name of the Lord. The thing that washes away our sins is calling on Jesus, not the water.
Baptism is a covenant sign.
The context is important. Now, baptism corresponds to something. The verse before it speaks about Noah being saved in the Ark and the floods destroying the wicked. But it is baptism. It is the outward sign, instituted by Christ to gain Grace.