There are many views on baptism, from baptismal regeneration, to baptizing infants, to believer's baptism. My view fits into the last category. But even within that last category, there are at least two views to consider: baptism based upon a valid profession versus baptism based upon fruits of repentance.
I heard someone say that there was no text in Scripture where baptism was ever denied. Immediately Luke 3:7-8 came to mind:
"He then said to the crowds who came out to be baptized by him, 'Brood of vipers! Who warned you to flee from the coming wrath? Therefore produce fruit consistent with repentance. And don't start saying to yourselves, "We have Abraham as our father," for I tell you that God is able to raise up children for Abraham from these stones!'"
This passage is about people coming out to be baptized by John the Baptist. Therefore, we need to take into consideration that this is John's baptism, which may or may not be distinguished from baptism in the New Covenant. Regardless, the text seems to say (note the parallel to Matthew 3:7-8) that John refused to baptize people unless their lives demonstrated that they had repented.
There is another passage I think should be brought to bear on this: Acts 8:9-24. This is the story about Simon. Simon is explicitly said to have believed (Acts 8:13). However, the question of the end of the passage surrounds whether or not Simon was actually regenerated. I'm not going to enter into the arguments of that debate, but I do believe that the text makes it clear that Simon was never saved. So, how does this relate to baptism?
Many people love to bring up the "immediate baptisms" that take place in Acts. But reading the narrative as a whole might temper the conclusion. A biblical interpretation maxim I live by is: description does not equal prescription. That is, just because something is "described," that does not necessitate that it is "prescribed" or commanded for us today. So, how do you know if something being described is prescribed? One basic method is to look in the entire narrative to see if the thing being described is repeated over and over again in a positive way. Acts 8 describes an "immediate baptism" in a negative way. Now when looking at the baptisms in Acts (Acts 2:41; 8:12-13; 9:18; 10:47-48; 16:15, 33; 18:8; 19:5), it is interesting to note that the second one in the chain contained a "negative" example and that all (except possibly the last) were immediate. Both of those ideas need to be balanced. I have many other thoughts about the specifics of those passages that will have to wait for another day.
I have a lot of thoughts on this that I'm hoping to have time to post on in the days to come.