Baptism is an essential core of Christianity. Peter charged his audience of 3000 in the first sermon after Jesus had ascended to repent and be baptized in the name of Jesus. Throughout Acts, all those joining Christianity were baptized, including Paul who later taught that Christians were inaugurated into the body of Christ through baptism.
Jesus commanded in Matthew 28: 19 that incoming disciples be baptized.
I'm sorry, but the teaching of reciting a so called "sinner's prayer" not found in the Bible at the expense of the practice of baptism that was vividly practiced in the Bible is false.
I am a Christian and I have never been officially baptized. All that I have ever been is "confirmed" in my church. So using my personal experience I would say that baptism is not required and a little bit outdated. That is not to say it is bad to get baptized.
Baptism is specifically mentioned in the Holy Bible as a Christian rite of admission with the use of water and the blessing of a holy man. The last time I checked, the Bible -- according to its adherents -- has not become outdated. Yes, they consider it still to be a neccessary ritual.
I think it is just an option in most versions of modern Christianity. The only thing that is necessary is that a person is saved. I think that baptism is just to strengthen faith and to show that you are loyal to the religion that you are being baptized in.
Being "saved" later in life by having a personal experience with Jesus seems to be more important in modern Protestant thought than anything else. Giving testimonials is the only way to get new converts. Someone can be baptized 1,000 times, but having a ritual dunking doesn't convince anyone to join the church. When the economic benefits of church membership are so important, there is less about ceremony and more about personal relationships with God.
Baptism is not necessary according to modern Christianity. It all comes down to your beliefs and practices because this is not an issue of right or wrong. It should be up to the person to decide if baptism is necessary to their faith. Christianity has definitely grown in a new direction and the person should not be judged no matter what they choose to do.