See this is what I mean by heavily debated. Letting Christ into your heart and being Baptized go hand in hand.
Like it was stated above, Christ was baptized as an example to show what happens in Baptism. The Holy Spirit descended on him AFTER he was baptized.
(1 Pt 3:21) Even goes as far as to state what happens during baptism and explains how you are saved.
Let me put it this way. You go to the doctor to be healed. The doctor diagnoses you and gives you a prescription. You accept the Dr's prescription, and your faith tells you in your heart, that the Doc is right. BUT, have you filled his prescription yet?! It is your full belief in him that moves you to fill his prescription.
This "be saved only by letting him in your heart" stuff came from the "mass marketing" of Christianity from radio and tv.
Tell me, isn't it easy to broadcast to people in their homes and get them to watch/listen to your program, by telling them to just accept Christ, say a "sinners" prayer and BAM!, they're saved, than to "risk" them going to a local congregation to be actually baptized?
Baptism IS a pledge of good conscience toward God. Just like fufilling that prescription is a pledge of faith in your Doctor.
With Christian Love