On rightnerve there is an incredibly interesting article on tearing shirts. Here is a snippet:

So Pop Quiz Time!
Why was Jesus baptized?

1. Baptism was better than tearing John’s shirt
2. For the remission of His sins
3. To be saved
4. As an outward sign of an inward faith
5. To be a member of the local church
6. To be an Elder of the local church

Understanding why Jesus was baptized is probably very important for any systematic theology. Here is from John’s verbal exchange with Jesus:

Mat 3:14 And John tried to prevent Him, saying, “I need to be baptized by You, and are You coming to me?”
Mat 3:15 But Jesus answered and said to him, “Permit it to be so now, for thus it is fitting for us to fulfill all righteousness.” Then he allowed Him.

Greg Perry’s article is worth consideration for understanding this.