No it is not!
Of course it is!
No because we are saved by belief in Jesus Christ being baptised is just an act of obidence
It is by grace you have been saved, not by works. Let no man boast...
Baptism is only a confession of faith not a requirement for salvation. If you say we need baptism to be saved, you're saying Jesus' work on the Cross isn't enough for salvation.
I believe it is necessary because the idea of being baptised is not necessary did not even come along until the 1500s. Also, God commands us to be baptised. However, you need to have faith and it is not just baptism that saves you.
Clearly, through passages like Mark 16:16, Romans 6:1-14, Colossians 2:11-14, Acts 22:16, and others, we can see that baptism is the point at which we are united with Christ, united with His death, and united with His Blood which washes away our sins.
It's a commandment that's an "essential ordinance", so yeah.