Only Spiritual Baptism Is Required
The only baptism that is required is the one done by God (the Holy Spirit) when He joins us into the body of Christ. And it is required!
Make every effort to keep the unity of the Spirit through the bond of peace. There is one body and one Spirit-- just as you were called to one hope when you were called-- one Lord, one faith, one baptism; one God and Father of all, who is over all and through all and in all. (Ephesians 4:3-6)
That baptism is when we are spiritually born --born again.
In reply Jesus declared, "I tell you the truth, no one can see the kingdom of God unless he is born again." "How can a man be born when he is old?" Nicodemus asked. "Surely he cannot enter a second time into his mother's womb to be born!" Jesus answered, "I tell you the truth, no one can enter the kingdom of God unless he is born of water and the Spirit. Flesh gives birth to flesh, but the Spirit gives birth to spirit. (John 3:3-6)
Does Water Baptism Still Have a Purpose Today?
Absolutely! It's not that it's required in any way --but it can serve very well as a point of reference. Water baptism is a way of providing a point in time to which a person can refer to and internally say: That's the day I became a Christian; that's when I was born again.
That's the day that I died with Christ; was buried with Him; and was raised to new life with Him. It's the day I became a new creation. When confronted by the enemy in times of weakness or doubt, with confidence I can say: Flee from me Satan, I'm a child of God; a brother of Christ; an heir to the kingdom! "And I remember the day it happened!"
Having been buried with him in baptism and raised with him through your faith in the power of God, who raised him from the dead. When you were dead in your sins and in the uncircumcision of your sinful nature, God made you alive with Christ. He forgave us all our sins, having canceled the written code, with its regulations, that was against us and that stood opposed to us; he took it away, nailing it to the cross. (Colossians 2:12-14)