Baptism is an important act of obedience. It is our public identification with Jesus Christ as our Savior, and with other Christians.
The blood of Jesus Christ shed on the cross is the only basis for the forgiveness of our sins. Salvation (or conversion) occurs when we place our faith in the death and resurrection of Jesus as sufficient payment for our sin debt.
Once saved, we are ready to be, and ought to be, baptized. Married couples show the world their love and commitment to each other by wearing symbolic rings. Christians show love and commitment to our Lord through the symbol of baptism.
Jesus instructed us to be baptized, so it is an important act of obedience. Baptism is not necessary for salvation, but it shows the world our submission to God and our identification with Jesus as Lord.