For me, this one is a "no-brainer" and right at the top of the list. The New Testament is full of references to baptisms and tells us that we must be baptized to be saved. There is no getting around it and no getting into heaven without it. (Please, spare me the wild, extreme "what if's" that seem to come after a statement such as this).
Let's start with Mark 16:16
"Whoever believes and is baptized will be saved, but whoever does notAfter Peter preached to the multitude at Pentecost in Acts 2, Acts 2:37-39 tells us that the people there asked "what shall we do?" and the answer was clear "Repent and be baptized". Paul went on to say that this was for "...you and your children and for all who are far off..." telling US that this commandment was for us.
believe will be condemned."
Some might use the passage about Paul and Silas in prison in Acts to prove otherwise. Acts 16:29-34 asks the question "what must I do to be saved?" Paul says, "Believe in the Lord Jesus, and you will be saved", but what happens next? "...then immediately he and all his family were baptized..." Paul took them at that "late hour" and baptized them, they were baptized as part of their step toward salvation.
Enough said here, this is really basic. God requires us to be baptized, to die to our old self and come up new.