When we accept Jesus as our Saviour we are clothed in His righteousness. We are fully accepted, and fully forgiven for every sin we have committed, and ever will commit, from the cradle to the grave. Paid in full!
It is clear in Scripture that we need to not only repent, but be baptised as well, following Jesus' example. This does not mean that the water saves us. Nothing but the blood of Jesus can get us into Heaven.
Baptism is the confession of our faith. We are baptised in the Name of the Father, the Son, and the Holy Spirit (1 Peter 3:21).