I realize there are many passages in scripture that don't rest in the black and white areas. We could play a theological ping pong match with the Armenian vs. Calvinism debate, wether or not Jesus went to hell for 3 days, Christ's impeccability and with eschatology, but baptism is fairly cut and dry.
Since this is a blog and not a book, I don't have a lot of time to straighten out all the scriptures that the COC has distorted and taken out of context, but I will deal with a few issues.
Although the COC do not have many scriptures to support their heresy, there are a few that give more trouble than others. One of the more popular scriptures used is 1 Peter 3:21, which says, "and this water symbolizes baptism that now saves you also, not the removal of dirt from the body but the pledge of a good conscience toward God."
The Church of Christ would say this means that the WORK (for we are not saved by works) of baptism plays a salvific role in our over all salvation. This is a classic example of first, taking scripture out of context and second, extremely poor hermeneutics.
Lets deal with the words used in the text first. The word baptism (greek = bapteesma) means immersion, which can be an immersion by spirit or by water (consider this in context when reading other COC writings on baptism). The word "saves" (greek = soezeye) in this text means to rescue or to save.
There are two important observations that must be taken. First, we observe it from a historical standpoint. The verse directly in The in front of V. 21 says, "In it only a few people, eight in all, were saved through water". Obviously, Peter is talking about God graciously sparing the lives of Noah and his family. Although the water was, in and of itself destructive, Noah and his family floated on top and lived. Moreover, Noah and his family went into the ark and left behind a world of iniquity. Therefore, the waters saved them. Peters uses the flood to represent baptism and baptism to characterizes salvation.
The next observation is to look at the text as symbolic. Peter said, "and this water symbolizes baptism that now saves you". "Noah's deliverance through the waters of the flood is seen as a prefiguration and type of the saving event of baptism". The nature of baptism is symbolic, not salvific. The flood waters cleansed the earth of man's wickedness, so the water of baptism indicates man's cleansing from sin. Baptism is seen as a counterpart to the flood. Peter uses baptism here to symbolize a life that has been regenerated by a gracious work of God and not man.
Finally, just a reminder; Paul wrote, in 1 Corinthians 1:17a, "For Christ did not send me to baptize, but to preach the gospel". If baptism were essential for salvation, don't you think that the apostle Paul would've included that little nugget in his letter to the church of Corinth? Instead, he makes a point to say that he didn't come to preach baptism. Moreover, he said that Christ sent him to preach something that wasn't baptism. The issue is this; baptism is a work. If works can save you, than that not only contradicts God's holy, inherent and infallible word, but it also reduces the work of Christ's atoning sacrifice. Woe to you Church of Christ. Repent.
Thanks to Simon J. Kistemaker for his insight from his commentary on 1 Peter.