what does the bible say?
The New Testament presents baptism as a command for disciples of Jesus and as the expected response of new believers (Matthew 28:19; Luke 3:21; Acts 2:41). The narratives suggest immersion as the ordinary practice, since baptisms occurred where there was ample water (John 3:23; Matthew 3:5–6; Acts 8:36–39). Baptism visibly identifies a believer with Jesus and with His people (Acts 8:12; 16:33; Romans 6:3–4; Colossians 2:12).
At the same time, Scripture is clear that salvation rests on grace through faith and not on any work, including baptism (Ephesians 2:8–9). For example, the believing criminal who died beside Jesus was saved without being baptized (Luke 23:43). Additionally, Cornelius received the Holy Spirit before being baptized (Acts 10:44–48). These and other passages indicate that, while baptism in water was the norm, those who could not be baptized were not second-class Christians.
The Bible does not provide specific instructions for those who are physically unable to be immersed. A church is free to apply wisdom in how an individual might make a public declaration of faith while respecting issues with water immersion, as long as the individual has made a true profession of faith.