Water baptism is an outward visible act meant to depict the inward spiritual reality that has been made possible through the saving work of the gospel of Jesus Christ.
Baptism, What & Why?
Baptism is a biblical-mandated ordinance from the Lord Jesus. The Lord, prior to ascending into heaven at the end of His earthly ministry, commanded His disciples to “make disciples of all nations, baptizing them in the name of the Father, Son, and Holy Spirit” (Matthew 28:19). Water baptism does not in any way aid in the work of salvation (salvation is by grace alone, through faith alone, in Christ alone; the gospel) nor does one’s participation in baptism garner us any more favor from God the Father than we already have received through our faith in Christ. To be baptized is to be faithful to follow the commands of the Lord (Matthew 28:19-20) and is the observable pattern seen so clearly in the book of Acts (Acts 2:41, 8:17, 8:38, 10:48). It provides believers the privilege to outwardly declare before a gathering of witnesses the work of grace God has performed in their hearts.
Who should be baptized?
Any person who clearly understands and has clearly responded to the gospel message as summarized in 1 Corinthians 15:3-4. Note, in the book of Acts the issue is understanding and response: Acts 2:41, Acts 8:12, Acts 16:31-33, and Acts 18:8.