Jesus did not said water baptism is essential for salvation. It is a public acknowledgement of your following of Christ. Our Lord's cross, which all realize is of inestimable importance, is mentioned 28 times in the new testament, but baptism is mentioned over 100 times. Certainly we can't treat it as non-essential. It is important to understand that we don't get baptized to get salvation , but rather we are baptized because of salvation.
Baptism is the natural progression of salvation.
This was the form used with Jesus, and full-immersion is the proper form of baptism. In the parable of the rich man and Lazarus, the rich man requested Lazarus to dip the tip of his finger into cold water and bring a drop to moisten his tongue. On the night before the crucifixion Jesus identified His betrayer by dipping a morsel and handing it to Judas. And when John in vision saw Jesus riding forth as the commander of the armies of heaven, Jesus's garments appeared to John as though they had been dipped in blood. This doesn't say we will do so, but we will know when we are doing something sinful and will have the choice to proceed or not.