Water baptism is simply the way one goes about placing their faith in Jesus Christ. Because many people totally misconceive the nature of faith they simply cannot comprehend how baptism can be the means by which one receives the grace of God. The primary reason for this is that these people perceive the act of faith which receives the grace of God as simply acknowledging things in the gospel message to be true and they think this internal act of believing is the means by which they are saved.
One can find many saying they must have "faith" and "believing" is simply "not enough." This is quite a red herring since "faith" is simply the noun form of the verb "believe". When the word "believe" is used by people in this sense they really mean
And this is the entire crux of the matter. When people use the words "believe"