Topic(s): Baptism, Salvation
The Bible teaches there are some things we must believe before we can be scripturally baptized. One is what you have already stated–a faith in the sacrificial death of Jesus for the sins of all mankind. Akin to this is the necessity of faith in the deity of Jesus (John 8:24).
There must also be a belief in what takes place when one is baptized. For example, those who obeyed the words of Peter in Acts 2 believed that their faith, repentance, and baptism were all necessary to obtain remission of sins. They were not baptized thinking they were already forgiven. Anyone who is baptized believing forgiveness was secured before baptism needs to be re-baptized.
Paul wrote: “In Him you were also circumcised with the circumcision made without hands, by putting off the body of the sins of the flesh, by the circumcision of Christ, buried with Him in baptism, in which you also were raised with Him through faith in the working of God, who raised Him from the dead” (Colossians 2:11-12 NKJV).
Note that the circumcision made without hands takes place in Christ. This circumcision made without hands includes the putting off of sins and takes place when we are buried with Christ in baptism. Therefore, one must have a faith in the operation of God that takes place when one is baptized. If one believes he is already forgiven before he is baptized, then there is no faith in the operation of God.
In connection with this thought, Paul said those who are in Christ are those who have been baptized into Christ (Gal 3:26-27).
Though baptism symbolizes the death, burial, and resurrection of Jesus, it is more than a symbol in that it requires faith in God to cleanse us from sin through the blood of Jesus Christ (Rev 1:5).