Years ago, a machinist at Ford Motor Company in Detroit became a Christian and was baptized.  He took his baptism seriously.  He had been stealing parts and tools from Ford for years.  The morning after his baptism he took all the stolen parts and tools back to his boss. He explained his situation and his recent conversion and baptism, and asked for forgiveness.
This response by an employee was without precedent.  Mr. Ford was visiting a European plant at the time, but he was cabled concerning the details of this matter.  His response was requested.  Mr. Ford immediately returned a cable with his decision: "Dam up the Detroit River, and baptize the entire city."
Jesus went even further.  In his Great Commission he ordered his church to baptize all nations (Matthew 28:19).  Why?
Why is baptism so important that our church would make its derivative, "Baptist" part of our name? Why does this action matter to us?
Over the years I have spoken to hundreds of people about this issue.  Most of them wanted to join our church from a different background regarding the practice of baptism, and they didn't understand why this issue is so important.  Perhaps you're asking the same question.  Or perhaps you've been baptized in a Baptist church but still have questions about your experience.
So let's see why baptism matters.

The word "baptize" comes from a Greek word which means to "dip" or "immerse." The word was often used in the ancient world to describe the act of dipping a cup in a stream, or washing clothing. To "baptize" something is literally to immerse it in water.

John the Baptist was the first person in the New Testament to baptize people. He baptized those who repented publicly from their sins and wanted to follow God in faith. Their baptisms took place in the Jordan River as a witness to their community.

When Jesus began his public ministry, he did so by being baptized by John. Of course, he was not repenting of his sins, since he is the sinless Son of God. Rather, he was giving witness to his faith in his Father and supporting John's work of preaching and baptizing.

Later, Jesus commanded all his disciples to continue this work of baptizing: "Go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit" (Matthew 28:19). Baptism thus began with John and is commanded by Jesus Christ for us today.

There are two reasons why you should be baptized: to be obedient to the will of God, and to show others your new life in Christ.  Let's briefly look at each of these reasons.

First, baptism is an act of obedience. As we have seen, Jesus commanded us to baptize every person who becomes his disciple.  The early church followed this command very carefully, baptizing those who became Christians at Pentecost (Acts 2:41) and those who trusted Christ as a result of personal witnessing (Acts 8:38).  Your baptism does not make you a Christian, nor is it essential for salvation.  However, it is a very important act of obedience to the will of Jesus for you.
Second, baptism is an act of witness.  The purpose of baptism is simple: by this act we tell others of our new life in Jesus Christ.  Again, baptism does not create this life; the water does not wash away your sins, nor does one have to be baptized to receive salvation.
Think of baptism as a wedding ring.  Putting a ring on your finger does not make you married, nor must you wear a ring to be married.  A wedding ring is rather a public statement that you are married.  It is a symbol which shows others your love for your spouse.
In the same way, baptism is a picture or symbol of your love for Jesus Christ.  Here's how the symbol works.
According to the Bible, when you receive Christ into your life, he makes you a new person.  As Jesus put it, you are "born again" (John 3:3).  The "old person" is who you were before you became a Christian; the "new person" is who you are today in Christ.  The "old person" has "died" in that he or she has been replaced by Christ and the "new person" he has created in you.
By baptism you picture, or symbolize, to others this experience.  In the act of baptism, when you are immersed under water by the pastor, you symbolize the burial of the old person.  When you are raised up out of the water, you symbolize the raising of the new person.  In this powerful way, you are demonstrating physically what has happened in your life spiritually.  You are witnessing to the world your new life in Jesus Christ.
Paul explained this symbol for your new life in Christ this way: "We were therefore buried with [Jesus] through baptism into death in order that, just as Christ was raised from the dead through the glory of the Father, we too may live a new life.  If we have been united with him like this in his death, we will certainly also be united with him in his resurrection" (Romans 6:4-5).
To summarize: you should be baptized to be obedient to the command of Jesus, and to show others that you have become a new person in him.  These two reasons make baptism your most powerful witness to your faith in Christ.