Written by Victor Stanley Jr.
In Romans 6 Paul hinges his entire argument on the correlation between physical baptism and spiritual rebirth. From this one can conclude that baptism should not merely be regarded as a surface level tradition done simply because it is what Christians do. Rather baptism carries with it much significance as it connects the believer, even if only symbolically, with Christ in his death and resurrection. As Mark Dever points out:
“baptism is performed in obedience to Christ as a confession of sin, a profession of faith in Christ, and a display of hope in the resurrection body.”
These are not trivial things to be passed over, they are pillars of the Christian faith. Baptism is a command given in the Great Commission by Jesus himself and reinforced by the Apostles.
So the question remains: Is a church that believes baptism is not commanded a true church?
Well, a plain reading of several passages of scripture makes clear that baptism is commanded, so on the one hand they are denying the word of God. However, even if one were to concede that baptism is not a command, it is still clear from scripture that baptism is strongly emphasized, and has been and remains a key practice in the life of the Church, thus it begs the question: Why would a church not observe baptism? It would seem that a church that fails to observe baptism, at best, fails to be fully centered on Christ and the word of God, and at worst is not a true church at all.
 Mark Dever, The Church: The Gospel Made Visible (Nashville: B&H Academic, 2012), 30.