Zac Poonen emphasizes the significance of baptism as an immersion in water, rooted in the original Greek meaning of the word 'baptism' which is derived from 'bapto', meaning to cover wholly with a fluid. He illustrates that both the baptism of Jesus and the Ethiopian eunuch involved going down into the water and coming up out of it, reinforcing that true baptism is a complete immersion rather than a mere sprinkling. Poonen argues that baptism symbolizes a burial, which can only be accurately represented through immersion, and highlights that only those who have died to their old selves, desiring to turn away from sin, are eligible for baptism.

We now come to the question : HOW should we be baptized? The word `baptism' is not an English word. The New Testament was originally written in Greek; and the word `baptism' is derived from the Greek word `bapto', which means `to cover wholly with a fluid' or `to immerse'. And this is exactly what baptism meant to the early apostles - an immersion in water. Sprinkling water on someone's head is certainly not baptism. When Philip baptized the Ethiopian eunuch, it is written that "they both went down into the water and.... came up out of the water" (Acts 8:38,39). At Jesus' baptism too, we read similar words - that He came up out of the water, after being baptized (Mark 1:10). In the New Testament, baptism was always done by immersion. Since baptism is a burial, it is obvious that only immersion can typify that accurately. For, after all, we don't bury people by sprinkling sand on their heads, but by putting them under the ground completely! This also makes it clear that only those in whom the old man is dead qualify for baptism - those who do not want to sin any more. For after all, only dead people can be buried! It's a crime to bury a man who is not dead!